Wanted to draw your attention to this great post from James Light on basic concept in the Packers' passing game. 

As Jim explains:

That's the beauty of McCarthy’s offense with Aaron Rodgers at the helm. It doesn’t always have to involve a ton of different schemes and audibles to be effective. Instead they can keep the concepts simple and consistent but be able to adapt to any look the defense might present pre-snap.

We tend to think of McCarthy's offense as this incredibly complex behemoth (an impression that Mike certainly encourages) but at its root, it's still much like Holmgren's West Coast Offense in that it runs a lot of the same concepts out of various formations. Lots of window dressing to distract the defense from the fact that the offense is only running a handful of routes. 

Anyway, read the post. Really good stuff with pictures and GIFs of the Packers offense at work.