You have a nice smile, you should use it more
Number 2 is the best pic, but only bc of the background
Take some pics with nicer backgrounds and smile at least in a couple, use one that you’re smiling in as a main
I’m not a fan of the 3 pic, it does seem like you’re slouching like John said
Also make sure you shave up your neckline before taking any photos
Seems trivial, but it matters