Tell the user how many items are selected

I also want this. But not just counting the number of items selected, but also still showing identical properties like dimensions, duration, frame rate. Right now, the area goes blank when multiple items are selected. Here’s a quick mockup:

I kept the blanked out thumbnail so the text wouldn’t shift, but on second thought perhaps that could retain the first item’s thumbnail if the dimensions are identical.

I’d also love a selection count in the timeline for keyframes. The Info Panel shows the number of selected layers, but goes blank for multiple selected keyframes. (A workaround is to select the keys and then hit copy, it updates to say “Copied n Keyframes”, but this overwrites anything stored in the clipboard.)