You can set each Super Block to any of these widths: full-width, 3/4-, 2/3-, 1/2-, 1/3- or 1/4-width. As you can see below, your images will resize themselves to fit the block size.

Be aware, though, that changing the block on one page will affect its size on other pages on which it is placed.

How to Work with Super Blocks
(External link to Editor Handbook)