For gym photos, a mirror selfie is only okay if you have an elite physique. It's a shitty photo for anyone, but if you have an elite physique it counterbalances it to make it acceptable.
https://www.youtube.com/watch?v=rAUwd4CAT1o
Your physique is good. Not great, and not elite.
Get a friend or hire a professional to take a good gym pic of you. Here one Ed_ took of me and then one he hired me to take for good examples of what's possible. View attachment 1