I worked at the local McD as a teenager and it was always funny to see a horse ordering something (the camera does not pick up the rider). Ours was near the end of a trail often used by people on horseback.

And since horse riders are legally equivalent to vehicles it's pretty much a "fine as long as you don't shit in the driveway" situation.

The “cars only in the drive thru” was mainly driven by insurance requirements; cars aren’t expecting pedestrians there.