I had said before that when trying to edit my signature, clicking the Edit button didn't help.
Clicking the edit button now works, and I was able to edit my signature.
Turns out that this new setup allows for there to be more than one image per line in the signature, so to get it to go underneath, I had to insert a break after the first image.
That's [ br] in BBCode in case any of you were wondering.
(obviously without the space after the first bracket, I had to put that there so it didn't think I was putting in a break.)
There's still that gap between the bottom of the signature and the bottom of the window, which bothers me a bit, but it's not really a big deal