A guest pushed in my shower wall tile. How can I fix it?
So you have two options here


Whistle past the graveyard and caulk it up good. It will fail at some point, but maybe not today? (I don't really suggest doing this)
Rip it down and fix it. Because you should never be able to do this to shower tile. You have serious issues. My bet is they didn't put the backer board up correctly (or support it with, say wood behind it) and just tiled straight to back board as a quick fix. 1/4" backer board would break this easily AND in the way you show.