Get in closer, crop the image so that the old man's hands are only visible (and his wheelchair). A little higher vantage point to include more water, and maybe shallow DoF with the plane of sharp focus on the boy if possible.
Or maybe don't include their faces, just focus on their feets
Thanks for comment. 70-300 G lens, limited.
Get on top of them and take a picture, sure enough to get a response from them and might lead to an interesting situation.