Clear drinks- I agree with the level of difficulty, or at a minimum, the perception that something is amiss- especially so in a martini glass- it can get weird fast!. In video, the eye doesn't have the same opportunity to *linger* as it does in a still shot and consequently all of the refractions/reflections, etc. can become an issue when you're forced to focus your attention on the glass and it's contents. It all depends on the client and what their perceptions and experiences are imo.
I shoot an iPad menu a few times a year. Each item is silo'd on white with a drop shadow....it's used in a theater chain that serves food and beverages. Tap the image and it get's large with a description....the *look* that the client likes is really very specific and feels that additional elements in the glass are a distraction to the contents. I build a very specific set for shooting the drinks and often use cut out's behind the glass (which take a lot of time to construct and place)- gets me about 90% where I want the drinks to be. I also typically frost the surface of the glass as well as a fair amount of post editing to arrive at what we thing it *should* look like...even if it doesn't in real life.