Publicly sharing or stating something, especially on social media or in a political context, that is intended to indicate and/or emphasize one's values or moral convictions. The term is often used in a derogatory way to criticize doing so as superficial or as intended to garner praise or admiration. I hope I'm wrong, but her anger about this issue strikes me as virtue signaling.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.