Giving directions to someone over the phone recently, I told the woman to turn at the public toilet. She was a bit stressed out by the non-conformity of Parisian streets and wasn’t processing the directions well.
“I don’t know what one looks like!” she yelled down the line.
My mind searched frantically for something American that might be similar. I said that they’re like small trailers, like garden sheds, like a port-a-potty but bigger.
Finally, I nailed it. “They look like a shower stall for a rhinoceros!”