Bristol-based Cameron Balloons designed the upturned balloon for pneumatics and automation company Festo which flew it near Berlin.
Cameron Balloons spokeswoman Hannah Cameron said: "We made two balloons that looked the same, but one was upside down and the other the right way up.
"They do cause people to do a double take when they spot them drifting along together. The firm wanted something different and this really does make people look.
"It was a tall order, though, in a lot of ways, for example the basket at the top is fake, and there is a real basket underneath, which is hidden by a special skirt that can be lifted as the pilot comes in to land."