I WONDER - Was The Giganotosaurus Clever?

The video discusses the gigantosaurus, a large dinosaur whose name means 'giant southern lizard.' Despite its size, the gigantosaurus had a relatively small brain, comparable to the size and shape of a banana. This comparison is amusing given that bananas were not known during the dinosaur's era.

Why is it considered funny that the gigantosaurus's brain was compared to a banana?

What challenges does one face when trying to imagine the appearance of the gigantosaurus?