Is this a gerbil? Or a hamster? What’s the difference? Regardless of what it is, it sure is surprised. Either that, or it’s shocked. Shocked and surprised aren’t the same thing. Neither are hamsters and gerbils, for that matter. I found some differences between the two at abcgerbils.com, but they are strongly biased towards gerbils, so take it with a grain of salt.
Gerbils sleep and play in small increments, rather than being nocturnal or non-nocturnal (dayturnal?). Hamsters are nocturnal, so if you want to see cute hamster antics, either stay up all night or put a video camera on them while they sleep. Hamsters are also more likely to eat their young than gerbils. Ew. Gerbils are desert animals, and are not as stinky as hamsters. Also, hamsters are more likely to bite you.
Incidentally, I have a buddy whose little brother once had a gerbil. He brought the gerbil downstairs and said “look! its eyes bulge” and then squeezed it and its eyes got all bulgy. I imagine hamsters would do the same. That pressure’s got to go somewhere. But, don’t squeeze your rodent. That sounded dirty. But still, don’t do it.