It has no "understanding" of a cat. It's an associative store with soft edges that pulls out compressed cat representations when given the noun "cat". The key store includes nouns, adverbs, verbs, and adjectives, and style abstractions, and there are mappings into the store that link all of those.
But they're very limited, and if you prompt with a relationship that isn't defined you get best-guess, which will either be quite distant or contaminated with other values.
If you ask Dall-E for "a woman made of birds" you get a composite that also includes trees and/or leaves. Dall-E has values for "made of" and "birds" but its value representation for "birds" is contaminated with contextual trees and branches.
Leonardo doesn't have a value for "made of", so you get a woman surrounded by bird-like blobs.
To understand a cat in a human sense the store would have to include the shape, the movement dynamics in all possible situations, the textures, and a set of defining behaviours that is as complete as possible. It would also have to be able to provide and remember an object-constant instantiation of a specific cat that is clean of contamination.
SORA is maybe 10% of the way there. One of the examples doing the rounds shows some puppies playing in snow. It looks impressive until you realise the puppies are zombies. They have none of the expressions or emotions of a real puppy.
None of this is impossible, but training time, storage, and power consumption all explode the more information you try to include.