Only number 3 conveys the concept of warmth to me. A wintry scene contrasted with orange tinged light visible through house windows is a classic trope to evoke warmth and cosiness. The interiors are undoubtedly a physically higher temperature at the location of the photographer, but that is not being communicated visually by the picture.
Most pictures lack snow. You'd expect the interior of a room to lack snow. Lack of snow alone does not communicate anything unless it's in a context where you'd normally expect there to be snow.
If I was a visual designer, and I was tasked with providing a picture to represent warmth, I might choose, I don't know; hands in mittens clutching steaming mugs of cocoa, a cat snoozing in front of a roaring fire, or what else? Welcoming light shining from the windows of a house in a snowy landscape! If I submitted a nondescript photo off of a real estate listing, and said "look bro! No snow", I'd be looking for a new job.
Two of the nine pictures lack snow. Not really most.
This is an automated little riddle one goes through as fast as possible to get to the website, doesn't really require any larger discussion on art or graphic design, as you not going to win it against a coded script.