I took a whack at it.
Glass, especially with liquid in it, is highly reflective. Also if the liquid is also transparent you can see the bottom of the glass as well. Also the sides of the glass should be slightly visible, because the liquid is only touching the glass, not occupying the same space. (this may or may not disappear depending on scale drawing though)
I think I lost the symmetry of the flask a little, but I was more going for the reflections and light.
You know, I just realized you wanted the sticker as a label. In that case I'd suggest drawing an ellipsis that is smaller at the top, and wider at the bottom so it appear as if it is receeding from the viewer. (but make sure it is receeding at the same angle as the beaker.)
For reflections and such, I'd suggest having a glass of juice and setting it in front of a good light and just study how the light is interacting with it.