There are a few options for this to happen, I want to suggest two, although the more likely choice in this case in my opinion is the first one: 1. A design choice - Ignoring true perspective to satisfy design (as Marshall also pointed out about the big arc in this drawing). 2. the chimney's top is a declined plane, making the close edge (closer to the camera/viewer) higher and the further edge lower. that would mean you wouldn't be able to see the top even though your eye level is above the chimney. Mind you, there are a few other "mistakes" in this image in regards to perspective. I tend to believe they happen both due to design choices, and just not making a concious deliberate effort to solve all perspective problems in advanced. As you study perspective, you will start to notice a lot of "mistakes" everywhere. some are intentional, some are not. As Marshall pointed out at around 00:16:00 - If it's deliberate - Great. If it's accidental and it works - Okay. If it's accidental and it doesn't work - That's when you take the time to solve these perspective problems. Hope this helps!