Figurative language.
When one uses figurative language, one does not mean the actual/literal meaning of what was said. Figurative language is just a figure of speech and is typically used to provide a better mental image to readers of what it is the writer is trying to convey by manner of exaggeration. Thus, because we all know that it is literally impossible for something to physically not be able to fit into an imagination, this is figuratively written—or figurative language.