Kate...on the new construction that I have seen, the crew boss will often have several houses going up at once, so he goes in and just inspects as the work progresses..often they will spray paint to point out a spot he thinks needs something, so when the crew comes in the next morning, they see what to fix. On that pic, up at the top, it looks likes there's a hurricane clip there? or something to secure the pieces...my guess would be they skipped a clip(if that's what it is)...or something along those lines...codes regulations designate everything from the number of fasteners in each application, to the spacing, etc...so the crews go along at a fast clip, and the boss comes in behind them and check, and marks!!