What should you do when you're walking by an ice cream parlor in Nebraska and spot an extremely rich man, and an extremely rich and famous man, sitting together on a bench?
Paul looks reasonably amused by the kid's candid shot, while Warren looks like he's either going to wave for the camera, or shoo the kid away.
Apparently Paul had a concert that weekend in Lincoln, Nebraska (thanks Lou!), and Warren still lives in Omaha in "the same modest home he bought in 1958 for $31,500" (thanks Miss C!), so it looks like rare moments like this may happen often in Omaha...