[simpss]

According to this[0] iphone 13 mini is 5.4" and according to the OP new SE is 4.7"

0 - https://www.apple.com/iphone-13/

[hammock]

Yes screen size. Look at the physical dimensions. https://www.apple.com/iphone/compare/?modelList=iphone13mini...

[bena]

That's the screen size.

The 13 mini as a whole is smaller than the SE because the SE has a top and bottom that's not screen.