I think this one's my favorite! This is the only Shortpacked!-themed one (the others were Dumbing of Age), though the only thing that really makes it technically SP! and not DoA is the "PROP 469" banner.
I like it because when I shade, I have a pretty robotic system that I go through pretty much always, to save time; but I ignored it here, and considered only light sources. Consider the colors on Robin's face versus how I usually do faces. Also, the anatomy was tougher here, with one person on top of the other. So it was an additional challenge. Leslie's leg is a little fatter than it would be usually, but it's resting on her other thigh, so it'd be squished a bit. That sort of thing.
Basically (as I said in Jason's description) I just love drawing people, and these gave me an excuse to give their anatomy some extra love and care. It's easier to do that when they're not covered in clothes.