In Linux Mint 19 x64 MATE, I noticed one day that Ctrl+Shift+E brought up some built-in/default emoji picker. I started using it after that, because of its instantaneous startup time.
After a fresh install of Linux Mint 19.3 x64 MATE, this shortcut no longer worked, and there didn't seem to be any app installed of this kind, and nothing in the Software Manager or first few pages of Google results seemed to be the same as what had been there before.
Unfortunately, I hadn't bothered to learn the name of the app, nor what it was part of/where it came from. Anybody know what it is?