King Corbin and his goons chained Roman Reigns up weeks ago and gave him a dog food shower. That receipt came around for Corbin this week.
The Usos and Roman Reigns faced King Corbin, Dolph Ziggler, and Robert Roode in a six man tag team match this week on Friday Night SmackDown. During the first segment they had a conversation and decided to add a special stipulation: Loser eats dog food.
WWE was running Loser Eats Dog Food matches at live events. These obviously went over well enough to go for it on television.
It was quite a messy scene to close out SmackDown this week.