Why do the giants in Shingeki no Kyojin start to look like the characters that got eaten? In Shingeki no Kyojin, Armin's grandfather dies when he is sent to recover Wall Maria. And in the episode when Eren gets eaten, the face and the look of the giant who eats him is exactly the same as Armin's grandfather.
 

Is this related in any way?
Because


   Titans are actually humans.


Read the manga for full explanation.