Inspired by you I did some investigation myself and I compared a few photos:
I noticed following features:
- Luke has characteristic freckles on the right side (his right side) of his nose - RED arrow
- The boy with his right hand wrapped is definitely NOT Samuel - GREEN
- Luke had longer hair in Ely, which could be easily swept up by the wind - BLUE
- Luke wears a noticeable watch - PURPLE
So, I think, it's Luke on the picture.
By the way, isn't it fun to have such photo riddles?