There are many different things that could explain it. They could have viewed it from somewhere else, or from a device whose location couldn't be resolved by FAA. (I notice lots of times the visitors that are from New York aren't really from New York at all, it must be what FAA reports as location when it cannot determine location.) They could have viewed it several weeks ago and put it in the shopping cart and then bought it from there without returning to the image page. I've also noticed that sometimes views fail to show up at all, so who knows?
There is no "normal" when it comes to views. In any case, congrats on your sale!