This article explains the books that were removed https://apnews.com/article/dr-seuss-books-racist-images-d8ed18335c03319d72f443594c174513
here is a couple of examples they mention
In “And to Think That I Saw It on Mulberry Street,” an Asian person is portrayed wearing a conical hat, holding chopsticks, and eating from a bowl. “If I Ran the Zoo” includes a drawing of two bare-footed African men wearing what appear to be grass skirts with their hair tied above their heads.
