It is the fifth waterproof jacket that Mary Kom has tried on in the central London sports shop and a yawning changing room attendant is getting bored waiting for her to make a decision.
"It's too restrictive," she says, handing him the jacket. He raises his eyebrows sarcastically as he takes it, evidently fed up of this picky customer.
Suddenly Mary Kom turns to the mirror, grimaces and aims a right hook at her own image. The attendant's mouth drops open.
The petite, five foot nothing woman in front of him has started shadow boxing at lighting speed, her fists almost skimming the glass, her wiry body rippling with an agitated, furious energy.
"Who the hell is she?" whispers the attendant to me, stepping back a few paces. "She's amazing!"
Mary Kom has come to the UK to take part in a test event for the London Olympics and she's giggling in delight as she takes in her first glimpses of the city.
She gets her husband, Onler, to take photographs of her peeping out of an iconic British red telephone box, and buys Big Ben key rings from tourist kiosks to offer to friends and family back home in Manipur.
It is her 30th birthday and she is out to have fun. We sit at a pavement café in the winter sunshine, drinking coffee and eating soft-baked cookies. She breaks one apart in front of me, watching the melted orange chocolate ooze luxuriously onto the paper plate.
"Ha!" she laughs. "We don't get things like this in Manipur with the economic blockade."
Mary Kom's homeland, Manipur, is a troubled Indian state where in the capital Imphal, at least thirty different groups of insurgents are fighting over territory.
One such dispute over the Sadar Hills area led to the two national highways being blocked for around four months, stopping essential supplies getting through. Hospitals had begun to run out of medicines, there were acute fuel shortages and food rationing.
In September last year when we were in Manipur filming Mary as she prepared for the London Games, her family was extremely worried about running out of fuel to heat their home and to cook with.
Her four year old twins, Reng Pa and Nai Nai were inconsolable about the complete unavailability of ice cream.
"Imagine how happy my kids would be with these!" says Mary, taking another biscuit.
Onler is looking baffled as we wander around Covent Garden together, forcing our way through the crowds of shoppers and tourists.
"It's just so strange," he says to me. "It's just so strange to be in such a busy city and yet not to see any policemen or soldiers with guns."
The civil unrest in Manipur is violent and unrelenting.
Almost every day there are bomb blasts, kidnappings and killings. Just over three years ago, Onler's own father was murdered by rebel gunmen.
Back in September at her home, I had tried to question Mary about the details of what actually happened to him but Mary had become so distressed at recalling the event that we had had to stop the interview.
When she had composed herself she told me that the unrest in her homeland was a constant worry to her and which distracted her from her preparation for fights.
"Every time I go away or go abroad for competitions, I am worrying is my family ok? Are my kids safe?"
Geographically isolated, Manipur has missed out on the economic boom that much of India has recently enjoyed and the state's political instability has halted much development.
And there is another fundamental problem for Manipuris which Mary jokes about as she steps out of cab onto London's Regent Street.
"Our taxi driver was Indian," she grins as she comes towards me. "And when I said we were also Indian he stared at us in his mirror and said no you're not, you're Chinese!"
Manipur is in the far north east of India and borders Burma and it is true that Manipuris share more physical features with the Thai or Chinese than they do with Indians. Many Manipuris feel that they've simply been forgotten by the central government in Delhi and aren't even considered to be Indians.
Mary hopes that if she wins an Olympic medal she could force India's attention towards her troubled state, perhaps prompting new economic measures, perhaps promoting fresh will to end the insurgency.
Until last year non Indians were banned from the war torn area because it simply wasn't safe enough to visit - Mary hopes an Olympic victory might even provoke a wave of tourists.
Later that night near the Embankment, we pass a flashy stretch limousine, presumably hired by girls on their hen night. Onler stops to take a picture.
"They must be so wealthy!" he marvels. "It's amazing!"
I look at Mary posing glamorously against the bonnet of the car for Onler's camera and I suddenly remember the words of her first coach whom I had met in the gym in Imphal.
"Mary came from a very poor family," he told me. "I remember a little girl with a torn tracksuit and creased clothes, but she was a little girl with amazing will power."
Mary has always believed that sport was the way out of poverty and she is passionate about passing that message on to Manipur's youth.
With her own money, won from her success in boxing matches, Mary has set up her own academy for wannabe fighters, taking boys and girls from 11 to 18 and lodging them for free in her own house.
The routine is a punishing one - each child is expected to get up at 04:30 and to put in at least a couple of hours practice before school.
When I watched the children training in the field behind her house one morning, I could see the same glint of determination that is always present in Mary Kom's eyes refracted in theirs. They looked shocked when I asked them if they got fed up of the rigorous training programme.
"It is tiring," admitted one young boy. "But it is a great opportunity."
In fact Manipur supplies India with a disproportionate number of top athletes.
One sunny afternoon I had taken a ride into the countryside where Mary grew up and was horrified to see peasants struggling to eek out a living from the fields and rivers, smashing stones for road construction companies for less than a dollar a day.
"If Manipur was a rich state," Mary had said when I had recounted my observations to her, "then it wouldn't be so good at sport. People here are used to doing really hard work. Hard work is their daily life."
A few more final photos near St Paul's and Mary, Onler and I wave goodbye. The next time we will meet here again will be in the summer when we all know there will be no more time for tourism.
As I hug her I think about the huge amounts of hard work that lie in front of her before the Olympic Games; the weeks of sweat and pain in an ill-equipped gym, and her constant battle to stay focused when the on-going insurgency continues to wreak havoc around her.
"I always remember the story of David and Goliath," she tells me. "David is a small boy and Goliath is a big man. How can David kill the Goliath?"
The glint of determination sharpens in her eyes.
"I always remember I am also small and Manipur is very small, but if I pray and if I do very hard work then I will win."
That sports shop attendant doesn't know quite how accurate he was with his analysis of Mary Kom. She really is amazing.