The Tail Hug
Note the tail held firmly in both front paws, the nose tucked carefully under the arm, the curled position, and yes, even the almost inside out ear. This could indicate a slight chill or perhaps trying to tightly contain a good dream.
The Tail Hug 2
Note the subtle changes from The Tail Hug 1. The nose is no longer buried, the ear is inside right, the hug not as tight. This indicates warming up and relaxing into a deeper sleep.
The Reach Out
This can be done with the body in nearly any position, the important part is the long reach of at least one arm/paw. It doesn't matter if there is anything to reach for, it's the stretch that's the thing.
The Rumpled Belly Up
Any kind of twist in the body only enhances this move. The rumpled tummy furs add a big cute factor. If the picture was not cut off, you would note the addition of The Reach Out to this pose. Curly toes are almost a must, of course they do tend to relax as sleep deepens.
The Chin Over
Yes, he's awake here for the moment, don't worry, it won't last. The idea in this pose is to hang the chin over the edge, the rest of the body is flat out above. It gives the illusion of looking down on everything and keeping an eye on everything, but in drifting off to sleep, it allows for some really nice snoring if the neck gets too heavy on the edge.
This is not a pose Leo uses much as he prefers to be upside down for the most part, but it's still cute.