With a compositing window manager, we have notification animations and it would be good to also have panel animation for when it shows and hides. https://twitter.com/shiori_leblanc/status/1254010829210636288
The panel already has a (configurable) animation when it hides in 4.15. It currently doesn't have one for showing. The main point of showing the user "where the panel goes" is achieved with the hiding animation. When I want it to be shown, I want it to be there immediately.