Preset macro icons in the User Macros interface have been revised.
Icons for skills and general actions have been replaced with a new set of macro icons. Skill and general action icons now require use of the /macroicon command.
Follows a list of available commands to use as macro icons, which contains, on the bottom, the emote icons. Problem is, while other icons appear to be working, the emote ones don't seem to work correctly.

My specific case is trying to put the "Change Pose" icon on a /changepose motion macro.
I've tried all of the followings, and none of them works.

/macroicon "Change Pose"
/macroicon Change Pose
/macroicon "Change pose"
/macroicon Change pose
/macroicon /changepose
/macroicon "/changepose"

Yes, the macro was in an hotbar. Yes, I tried both shared and permanent hotbar. Yes, I tried switching jobs. If I'm writing a bug report it's because I can't think of anything else.