Yes, it's possible someone reaching down from the saddle of a horse could spill hot coffee over a server. I wonder if they serve lorry drivers? I dare say there's a porch thingy with a height limit that makes it impossible. But what if the horse rider dismounted, would they serve them on foot (or a pedestrian)? (Yes, I know this bloke got a coffee on foot but he had to tether his horse and go into the actual cafe part to get it.) Kind of related, I note (from passing a particular McD's regularly and seeing through the windows) that at least some (non-drive in) branches seem to have done away with things like staff taking orders; you order and pay at one of a number of screens, then go to a hatch to collect. At least, that's certainly what it looks like (Bristol Cabot Circus branch, if you want to know)