Mike Piazza signs "Live Signature" cards

I don't really understand what this is about and I won't be "chasing 'em," but this looked kinda cool. Big fan of Mike Piazza.

We had @mikepiazza31 sign Live Signature cards for @ToppsBUNT! Download the app & chase 'em. https://t.co/NWVRqSv4e3 pic.twitter.com/kaRqaorNEl

— Topps BUNT (@ToppsBUNT) August 6, 2016