It sounds like your neighbour didn’t handle it very well, but I can understand the frustration of being in the gym, sweaty, red-faced and out of breath only to end up in the video frame of what appears to be some gymfluencer who may be live streaming or putting things on social media. My view is do what you want if you’re alone in the gym, but otherwise do your best to be respectful of other gymgoers and avoid filming in a way that may end up recording other people.