The Sausage Party is a very nice animated film that shows us how the life of supermarket products, which have a pedestal to human buyers. They believe that when a human takes them, they go to a kind of paradise they call the “Great Beyond.”
Frank is a sausage from that supermarket that is looking forward to being taken off the shelf next to Brenda, his girlfriend. She is a hotdog and the two want to go one step further in their relationship.
That opportunity comes to them when the two are put into the shopping basket for a celebration by a human basket they share with a mustard pot that had been returned and put back into the basket.
The mustard boat, which has seen what is in fact the Great Beyond, tells the rest of the product that this paradise does not really exist and has little to do with what they believe it to be.