Not sure if there is a reason for this but I've noticed if you drag an image onto another image from the bitmap gallery the gallery scrolls back to a previous position instead of staying where you dragged the image from. It kinda disorientates you and you have to scroll back to where you were to grab the next image. But if you just drag straight onto the page it stays in position where you just dragged from, I find this better especially if you are replacing a few images in a row.
