Hello from the future. The number 6 on the numpad of some keyboard setups is on the right side of the numpad. I am not confident that's the intended way to figure this puzzle out but it's what made sense in my head two years ago. The numpad buttons 2, 4, 6, and 8 also function as directional arrows, so that might be why I concocted that solution.
that was a character model left over from succubus labyrinth the game they were working on before this it was more or less a sequel(or prequel) to succubus maze never got finished maybe some copies of the demo are still floating around somewhere
edit
she's not in the public demo but you can still grab the public using the wayback machine