Somehow, the image’s irregular border fools my eye into thinking it’s a more interesting setting. My brain reads the dungeon wall as a Great Wall of China-style outside wall, with a white sky above it. The two adventurers are standing before a gate, holding off undead. I imagine the walls continuing for thousands of miles in either direction, protecting – the Fallen Lands? – from a continent’s worth of undead. Now that’s a setting!
Oh, so here’s a difference between the PHB and HotFL. The PHB subtitle is “Arcane, Divine and Martial Heroes”. The HotFL’s is “Create and Play Clerics, Fighters, Rogues, and Wizards!” The HotFL subtitle has a certain something that the PHB subtitle lacks. And that certain something is an exclamation point!