If you guessed - making roof panels then you're right! Apparently roof panels don’t come pre-molded, instead they shape the raw tin right on site. Seemed a bit weird to me, but what do I know?
In any case, I'm happy to see the roof going in. Not only is it satisfyingly shiny, it will protect all that hard work underneath. This picture is actually several days old so I'm hopeful that the roof is finished now. The insulation has already been done and they started drywall this week - yay! The next big projects will be flooring, and the installation of all the bathroom fixtures, kitchen cabinets and appliances.
My folks will actually be on site for the next few weeks, escaping the cold, supervising the kitchen and bathroom installation and doing some of the construction stuff themselves. I'm lucky to have parents who spent my whole childhood doing one home renovation or the other. Thanks in advance for all the help guys!