Broccoli says, "I look like a tree."
Walnut says, "I look like a brain."
Cashew says, "I look like a kidney."
Banana says, "Can we change the topic please?"
Listen here, Shrutik, you think you're so clever. You're not. Let's break down the joke, which is about food and shapes. Broccoli, walnut, and cashew make statements about what they look like (tree, brain, kidney). Then the banana, in a classic move, is like, "let's not talk about it," because a banana isn't gonna compare itself to a body part and is generally a smart food. So it's funny cause it's the one that wants to change the subject, like a coward. You can't even see the humor in that? Come on, brah.