The centaur idea refers to the ant's front legs not resting on the ground, not to the double thorax. I found that jarring too, but the ratings are based on appeal and HTC is apparently being rated as elegant abstract art. Compare LG's rating of "This ant is wrong in every way, and yet I can't stay mad at her. 7/10"
Looking more closely, the most disturbing thing I see in these is the Google ant, which has somehow placed its left front leg over its left middle leg. It feels like a layer mixup; that position is completely impossible in normal motion.
