You can barely see what there drinking, there not wearing the typical uniform (this in it's self would be a CLEAR indication that they were on a DAY OFF, or off duty, not too many companies let there pilots rock up in jeans and shirts riding a horse), alot of people are animal friendly and would feel this photo installs a sense of calmness if a horse isn't spooked (in the horses eyes by a large thing that has bits hainging off it). seems like good clever, simple, friendly photo.