In this image all is not as it seems.
In fact you would have a very hard time indeed filling these glasses. They are actually hanging under a high shelf as is typically found in many bars. It is interesting that by removing the context, ie the surround features which would have made the orientation obvious, we immediately see a glass ready to fill instead.
... Sláinte!
Photo: Robert Rath, '366 Days of 2012, Day 346 - Fill Time'. 1/160s f/2.8 ISO3200 165mm