I think I took the large amount of space as a kind of inventory, so I was surprised they weren’t grabbing already placed objects in the space that I thought they wanted. If it had been labeled as a “pick up” area or something, that would have been better. Or even just a simple tutorial for the first customer.
Alternatively, if I had been able to move around the already placed objects, I think I also would have figured it out more quickly, and that would have generally been a bit more in line with my initial assumptions, while still requiring me to figure out what the customer wanted (or at least guess quickly).