This is correct. 2011 did not have the small squares, 2012-2015 do have the small squares.Yes, there are different taillights.
The ones that are consistent all the way across (right picture) are the original lights from 2011. The ones with the square patterned reflective patch were introduced in either 2012 or 2013 (I can't remember).
Those are not Ampera tails, these are Ampera tails, unless the Ampera Tails changed a bit from 2011-2015 (or when it ended)?Then there's the Ampera version: