Why would a girl do that? Chancing it or ego- the worry that not enough online hits means not enough attention?
Firstly, allow me to refer you to an earlier post:
As a Man, accept that you will never fully understand a woman, no matter how long you spend with one, they will always be able to puzzle you with how they see a situation. To which your reaction, naturally, will be “wtf ??”. Know this, be ready for it and enjoy the rest of the ride.
Secondly, I’d hesitate to say only women do that. For all I know (and it wouldn’t surprize me) some men might make that mistake when throwing up a dating website selfie.
However, I’m with you. Being honest, including using recent pictures, is the only way to be. Pity I’m not photogenic.