That first screenshot reminds me of something that we will get to do again soon (maybe).

During the Hallows End event at the end of October when you can get the temporary broomstick mounts, you can actually use a macro to bug out your character's look.

Code:
/dismount
/use Magical Flying Broom
Keep in mind that last year the broom was an instant-cast mount. The first macro use will mount you normally, but the second use will cause you to dismount and mount instantly, which the interface doesn't keep up with. You end up mounted, but you visually look unmounted. With the fast brooms, you look like you are running at 200% speed (broom is +100% speed), basically like a rogue with sprint constantly on. With the flying broom, you swim very fast through the air. Other people see the same thing, but only if they were in visual range when you did the quick dismount/mount.

Something tells me they may have that visual bug fixed this year. If they slap even the 1.5s cast time on the broom, then it won't work.