The Stanley Cup is used for a variety of purposes. It's often taken to parties, tossed in the pool and was even used as a baby crib earlier this year. Chicago Blackhawks center Andrew Desjardins got his day with the Stanley Cup and used it as a giant cereal bowl.
That's appears to be at least a full box of Lucky Charms. Hopefully the Cup got washed since Antoine Vermette put his baby daughter in it, otherwise that cereal may have tasted a little funky.