The anatomy of a white button-down

One of my goals for this fall was to make myself a white button-down shirt.  I already have three white button-downs, so why did I think I needed another?  Well, that's a good question.  As I've been working on it, though, I've come to realize how different each of my store-bought shirts are. Before I reveal my own version, I wanted to share my others as a reference point.