That is pretty darn cool.
Sonny: Generally, a horse that just has his ears pointed toward the back with a level topline and soft eye is an attentive horse. However, you have to take ear position in combination with all other aspects of the horse to know what it means. Rear facing ears on a horse with it's head up, nostrils flared, and eyes wide is generally a horse that is scared of either the rider or something behind him. Same ears with a lowered head and bared teeth is aggression. Some horses do completely flatten their ears when they are concentrating: you will most often see it on cutting horses or reining horses and sometimes on horses when they run.