Right now transitions are a bit clunky, and we are missing some kind of notification in the place where you clicked. The way we are doing this in the all layers page is:

1. When you click the 'add layer' or 'delete layer' buttons we fade out the button 

2. We replace the button with a message telling you the number of layers added / deleted. The message gets out of the way after a little while, and 

3. We then fade in the opposite button to the one you clicked

4. We also show a notification at the top of the page, which stays until you dismiss it or it is replaced by a newer one

We should do something similar in the layer details page.