Gym mirror moment turns into a laughing, gold-chain hangout

In a gym in London, United Kingdom, a group of women are gathered around a mirror. The woman in the foreground, with blonde hair and a black top, is laughing and holding a gold chain. To her left, another woman with blonde hair is in the background, looking at her phone. Further back, a woman in a dark top is standing with her arm raised, possibly taking a photo. In the reflection of the mirror, a man in a grey t-shirt is taking a photo with his phone. The gym has wooden walls and appears to be well-lit.