[Soup]

The probably used tree branch brushes for the shading. As for the characters they could either be renders from an actual image or drawn-out from the person who made it and then rendered.

[Slim]

Oh . Do you think you can do that too?

I actually didn't realize there are branch shadows placed on top of the renders - Valentino is right, this will just be a brush.

[Ruskin]

My High School has a Photography class, and you learn how to edit photos in photoshop too. this is some stuff for semester II or III of the class, but I have seen plenty of this type of work being done by peers of mine. It looks good, however I agree the shadows are not there. a mistake many people make in first and second semester photography class.