A couple of people have said this, and I kinda knew it would be a point of contention. But, the Vex eyes are typically robotic, and the only "attitude" they have is kind of determined by how the audience percieves the face. I wanted to build on the idea that the Vex could have expressions, created by mechanical shutters around the eyepiece. In my concept here, the Purge Conscript is almost squinting, scanning it's surroundings or perhaps locking onto a target. I feel sometimes the Vex are quite lifeless, and quite right from a lore perspective, but from an aesthetic perspective, they feel a little empty. That's just my opinion.