Elephant in the room is a direct reference to the popular homonym expression used when there is a subject that needs to be discussed, but that everyone is avoiding. The elephant, as a metaphor to the problem avoided, is literally materialized in this scene, and appears to be already a part of the family household, since he, himself, informs his companions that the supplies are running low.

 

If the couple decides to buy more peanuts, perhaps the elephant will remain distracted for a while longer, but the more he eats, the bigger he will become, thus invading the couple's space even more and making them have a harder time removing him from inside the house. Metaphorically, the elephant's speech reminds us that the strategy of avoiding confrontation, which may be comfortable in the short term, often only means the risk of an even more complex problem later.