It's hard to tell with just this picture, but the Rhino Smile appears to be pushing what looks like a chariot for Sasaki.
When you look at the horns protruding from the side of Sasaki's seat, combined with the Rhino in front, it gives a similar silhouette to a Triceratops, though deviating enough not to tip you off.
Though Ankylosaurus would make sense too, since that's the armored dinosaur.