It's a cardboard popcorn container that can be used as a megaphone when it's empty, by pulling out the end cap at the bottom. It has a simple scoreboard printed on it and a place for autographs.
This one happens to be signed by Vic Power and Earl Battey, in relatively random places, not in the predesignated autograph section.
Someone wrote the date and attendance on it (July 17th, 1963, 42,034 in attendance). The Twins lost to the Yankees 0-4. Joe Pepitone and Elston Howard hit home runs off of Lee Stange. Zoilo Versalles hit a triple but also made an error.