The two guys really fight for attention, pulling the eyes to each side simultaneously. And then there's that empty space in the middle that doesn't help to hold the eyes from wandering to the edges. Then there's the backhoe and the tiny operator which would normally be the main subject...they're barely part of the composition at all, but at the same time they complete a nice triangle with the other two players in this scene. All-in-all it's very quirky and full of tension. Fantastic job you've done here.