No pongas esa cara

Question

Is this like, don't wear that sad face, turn that frown upside down? Gracias.

Answer 1

I think it is the equivalent of "Don't make that face," which could be taken to mean "Don't wear a sad face," but it could also be something a parent says to a kid who's pouting or otherwise being annoying.

Answer 2

"Don't make that face"/"Don't look at me like that"

I imagine it could be used in various circumstances, not just to tell someone to cheer up, if he/she appears to have a sad face.