I like this picture alot! Behind the "mystery liquid", the background shows presence and closeness, but blurred enough to be indistinguishable. Gives a comfortable feeling, unlike those other kind of images that make you feel like you are falling off a cliff :-). Now on to the guessing...Japanese was a gimme because your profile says you are in Japan. I would have said bottled water, and looking up "sukoyaka" in google would confirm, if it was the name of the beverage, but that would be cheating. The inside of a nuclear power generator? Liquid plutonium contaminating a flock of Dodos? A large, simmering vat of cow snot? I give up...
"sukoyaka wo shiyou shite imasu"? Uh, looks like an oversize test tube on a chrome surface ... with water inside and bubbles ... Actually, this could just be a glass with something like and advertisement printed along the side ... and containing a cleaning agent for third teeth. Mwahahahaha ...