If you start dragging a picture over the image search bar, Kagi should automatically bring up the "drop an image here to search" UI. This is useful, as it saves a click, and you don't need to anticipate the need to do that before you start dragging.
Google Images does exactly this:
If you attempt the same in Kagi without first bringing up the RIS dialog, the browser will simply open that image in the current tab:
