What it definitely can’t be is a cup being rapidly pulled off anything - because that just doesn’t happen. Even if it was jelly or ice or whatever, you can’t just yank the cup away, because in order to clear the contents, the cup has to fill with air, or else it takes the contents with it.
The splash is definitely fake. If you go frame by frame, the hand above the water disappears. My guess is that water was thrown onto the table and edited in.
I’m pretty sure it’s not ice. To get ice that clear, you would need to boil distilled water to get all the dissolved air out of it. Also, it had a flat surface where it contacted the table. Also, I didn’t see condensation.
I’m also sure it’s not water. If it actually was water, there would be a miniature whirlpool in the center because of the twist. You can verify this by rotating a bottle of any liquid with your hand like you are playing with a sparkler.
I don’t think it was gelatin or a sugar cube either. There was no shaking or any cloudiness to the water.
I doubt it was CG. When the camera moved forward, there was no dithering as the object was resized. Usually, when working with 3d objects, distance is a function of size. The farther away, the smaller it is; the closer, the larger. When they moved the camera closer, it didn’t seem to change size unnaturally.
My guess is going to be a a piece of clear plastic melted into the shape of the glass, and then sanded to look like ice.