Crafting area seems wonky? Is it drawing LoS as if firing a weapon?

Exhibit A:

I am attempting to build a locker in the square to my southwest. I have sheet metals in the locker which is three squares up and one to the west. I cannot build a locker, despite having all the materials on-hand and well within the craft zone.

Exhibit B:

I am now able to build a locker, despite being one square farther from where I was. I am forced to conclude that this owes entirely to the fact that lockers are LoS blockers. I think I’m going to wind up making everything Dressers at this rate.

Yes it’s based on LoS.

It also seems to not care about vision, only gunfire-LoS, because if I put a container I can see over - such as a dresser - between me and something I want, I can’t get at that thing.