This is really good, a great example of creating emotion without emotive features. My own personal thoughts…
Don’t add a volumetric light from his eye, there are no airbound barticles to catch the light. The scene is clear and a volumetric light would just look false. I find you have to be careful with volumetric lights, they border on lens flare status personally.
I don’t see this as a war picture, to me it is a picture of a lost soul. Caught in the indecisions of his own mind and struggling with the emerging emotions that he may have been programmed not to have. If there is a war then maybe he is no longer part of it, perhaps he is now fighting his own kind for his own survival.
Perhaps cast out for showing the signs of emotion, his rusted state indicates a period of neglect by repairers and shows in a way his mortality. Life wears you down and the rust seems like the equivalent of human wrinkles.
The eye is fine, it’s simplicity conveys the basic emotional level it is perceiving the flower. It might not know what a flower is, it just knows it is different. It’s almost like a glassy eyed baby looking at things that it doesn’t quite understand.
If I had any crit it would only be the shade of the grass seems a little cold and blue. If they are being lit through a fractured cloud by a solitary sunbeam, maybe they could be a bit warmer
All in all, a very good image which achieves it’s goal, well done.