Subtle progress, major progress

As we get closer to a finished house, we have begun to realize that some days result in very subtle (or at least unexciting) progress, while other days seem to have great leaps forward. For example, over the past week we have seen the electrical plates installed in the house...


But we've also had sinks and toilets installed...


And also our water heater (not subtle, but also not very "exciting")...


We've also continue to find unusual stuff around the house, like this...


Yes, that is a rusty nail sticking into a Powerade bottle (which has some liquid at the bottom). This was just sitting on our kitchen counter. I don't have a clue where this comes from or what it means, but Emilie suspects that it is the result of target practice with a nail gun. Any thoughts?