What's wrong with this user interface? Perhaps there is a danger of the user putting their hand inside the top of the device and pouring coffee through the loop on the side. Once the user has figured this out, and put coffee into the hole in top, they do run the danger of resting it on it's side when they put it down. None of that seem possible? Is the user interface that you design as foolproof? This stash contains ideas on good design.