It's a new age m'lady.

Back in the day, redditors used m'lady to be condescending towards cis women and be their cringey idea of "classy" alongside wearing a fedora. That kind of thing is pretty dead.

Nowadays, chasers say m'lady to virtue signal to trans girls that they see them as their real gender. This is all the rage rn, I see it all the time from trans girl reply guys. Same vibe of "look i'm showing you basic courtesy now will you show me your tits" though. Also kind of an uncomfortable indirect emphasis on someone's trans-ness if that makes sense.