Seems like some random toy store. Not sure where tho. I know some sets will show up on shelves early in like Walmart or Target, but if you try to take it to check out to pay for it, they'll say you can't buy it yet. Really, they're not supposed to display them, but I don't think the workers care, lol.
I know you can pre-order them on the Lego site, but that's different. I've actually heard of people getting their sets early from Lego when pre-ordering.
I ordered the Sanctum Sanctorum yesterday, and didn't really care about it being on backorder because I wanted to get one as soon as they had more. But I got over 3k points and a GWP with it, so I can't complain too much. I kinda hope they send it early tho, heh.