On the one side, if there wasn't that screen door between them, those sweet, sweet Goldfish crackers would be snatched up in an instant. Since baby boy can't eat at a table properly, there was no choice but to lock the dog out. On the other side though, this is torture for the dog. Put a hood over it's head or something so it doesn't have to sit there being taunted by the snack he wished he had.
That's a black lab, which means that there is nothing safe around it. A black lab will eat just about anything, including the grossest things you can think of. A black lab would devour a tennis ball if bored, but if that tennis ball rolled around in mud, they'd snatch it up in a second like it was a chocolate covered apple.