"Yes, one of the Shades that Father assigned to maintaining the House," Zagreus says, as if this were a completely normal thing to have in a divine household. And to him it was normal.

Hades was Lord of the Dead - so of course, he had the dead do his bidding and work in various roles in the Underworld. The Contractor wasn't unusual that way.

"I don't like to sit, but...sure, I wouldn't mind a demonstration," Zagreus says. And he does dash over to the brick and bring it back to the table. But rather than use it as a footstool while sitting, he just decides to stand on top of it.