Depth is when you can look at the objects in a picture and tell distance and size in the foreground and background just by looking at the picture.
Shallow:
A volleyball in the field, and Rachel in the classroom. The others are their originals.
Large:
The grass in the field, the swinging bars on the playground, Abigail on the playground, the next two are the monkey bars, the tunnel on the playground, and a tree. The other is the grass's original before editing.