[toast0]

I've been in plenty of department stores with windows though. And I don't think I've been to any that drew a false sky on the ceiling. Many stores and malls have skylights too, although when they're the translucent ones, they might be also uplit, so you might not notice it's dark outside.

I think there's at least a difference of degree, but I think it's more than that.

[bobthepanda]

Department stores want you to be intrigued and maybe pick up extra stuff on the way to the thing you actually want to buy, but they don't necessarily want you to loiter. Idle loitering doesn't get you more purchases, at least not immediately.

This is different from a casino, where the most likely thing you'll do if loitering is to sit at a table or machine and gamble more.