I sure wouldn't lay between the feet like that, I have been kicked by horses laying down when working on trimming unhandled youngsters. Usually you are safe up by their shoulder or neck, some young ones seem pretty quiet but may decide to roll over or pop up without much warning.

"It's really quite amazing what a horse will do for you, if he only understands what you want. 
And it it's also quite amazing what a horse will do to you if he doesn't." ~ Bill Dorrance