What problem does this address?

Some users are confused about the difference between the "text over image" and "caption" icons in the Image Block Toolbar:

What is your proposed solution?

1. The caption icon could show the dotted line beneath the rectangle, as that is how captions usually appear
2. The "text over image" icon could maintain a rectangle all the way around the "A" to make it clear that it's not going to appear at the bottom of the image.