Pop doesn't really have very lucid moments all that often, but he has had two regarding this picture. He loves to pick it up and look at it. He almost always comments, too. "This is a really great picture" or "Aren't these kids cute?"
Though he might not always remember their names or who they are to him, he looks at this picture with affection in his eyes.
P.S. This is a 25-year-old picture of his grandchildren.