Alright kiddo, have you ever seen a picture or a drawing where someone's arm or leg looks really close to you even though you know they're far away? That's called foreshortening!
Foreshortening is when artists make things in their pictures look closer to you or farther away than they really are by stretching or squishing them. This helps make the drawing look more realistic and 3D, kind of like a pop-up book.
So if someone in a picture is holding their hand out toward you, the artist might make their hand look bigger and closer than their head, even though in real life their head is definitely closer to you. It's kind of like playing with perspective and angles to make the picture more interesting and cool to look at.
So that's foreshortening for you! It's just one of the ways that artists use their imaginations to create amazing artwork that looks real and exciting.