2 girls 1 cup... of coffee. Sorry as already mentioned the coffee looks a bit... solid 
Aaaaanyway... Maybe the cup should'nt be filled to the max. A little of the inside of the cup showing would look great I think. Owerall nice pix.
The blinking could be explained by the fact that the mug is pretty loaded with caffeine... bad joke but good piece. I agree with WindWhisper, the coffee looks like it's bulging up and the wink could be slowed down. I like the shading on the mug though.
I agree, its wink is too fast and don't look "natural" for a coffee cup.
This is cute, but the constant blinking is a little distracting, and having the shine on the "coffee" towards the light source makes it look more like pudding.
Like any fluid, coffee tends to dip down in the middle, so the the edge of the cup should shield the closest part from the light (unless the coffee is almost overflowing).
The biggest problem here is the liquid of the cup. It's consistancy isn't much like liquid at all.
I think it was said below, it looks a bit like pudding. :(