This stinks
Having stinky feet is just a regular part of flying. You’ve been sitting in an airport terminal for hours and haven’t showered yet. We all have a certain level of tolerance toward BO when flying, but if you do what this inconsiderate passenger is doing, you’re only going to make things worse for everyone.
For some strange reason, this person thought it’d be wise to stick their sweat-and-bacteria-filled shoe up toward the air conditioner. Eventually, everyone will get a good whiff of this person’s nasty feet stench while trying to sleep or eat. Do airplanes really need to warn their passengers not to do this? Apparently so… How disappointing.