Rear Window Defrost (strips)

[GMC-AT]

I noticed today my drivers side rear window doesn't have the brown defrost strip on the bottom of the window. The passenger side has them all the way around.  Can someone else look at their truck?  Not a big deal, just not sure if that's by design or a screw up on my truck.  Seems weird they would do that by design..

[mafd2]

My RST with slider driver side pic. Passenger side has 2 larger strips under the 8 thin strips that drivers side doesn't.

[GMC-AT]

Yes, I should have noted only sliding rear windows.  And I'm just talking about the large strip at bottom.  Ok... looks as it's by design. Weird though..