I think he looks the youngest in this photo with Joy
The photo with Alexei pushing the child's wheel barrow with the dog is standing with it's tail toward the camera. We cannot see his forelegs very well, so, I'm not sure if they are white with freckles. If taken before 1910 then it probably wasn't Joy. However, the back of the dog's neck has the white just like Joy's.
The dog on the hay stack with Alexei appears to be dark and because of the shadows I cannot tell what kind of dog he/she is. And, the dog doesn't have the white markings of Joy's.
AGRBear