The food inside the can is a processed cheese sauce. It is in a spray can similar to the secret sauce in "Patty Caper," except it does not have an X on the bottle.
Role in episode
SpongeBob sends special invitations to various people of Bikini Bottom, promising each thing that they love will be over at his house. Excited, everyone arrives at SpongeBob's residence, only to find out that they have been tricked into viewing a vacation slideshow.
SpongeBob receives complaints about the low resolution of the slideshow images. He apologizes and tells them that Patrick got Cheez Fizz all over his camera. This scene cuts to a flashback involving Patrick attempting to spray the cheese in his mouth, only to aim at SpongeBob's camera instead. The end results of the pictures came out orange and blurry.