Open a qrc file in the resource editor.
Left-click an image you want to delete.
it's opened and you have to go "back".
After that you can click "remove".

2 extra unnecessary mouse clicks.

Suggestion: Add "Open" and "Remove" as a context menu items.

Anyway, after clicking and going back, now you can click on the "remove" button in the button bar below, because an item was selected.

Now try to delete another image. Right click on it. see context menu. don't do anything.
Then click on "Remove" button below. Nothing happens.

The thing was not selected unless I left-click, which also has the side-effect of opening it.