A hump shaped for a passenger
Yoshi’s red back detail is drawn as a saddle: a piece of riding equipment, rather than a hard shell that happens to sit on his back. That distinction changes how the character reads. A shell suggests an animal’s protective covering; a saddle suggests a place for someone else to sit.
The design makes the gameplay legible
Yoshi’s role includes carrying a rider. The saddle turns that function into a visible feature, so the relationship between the characters is built into Yoshi’s silhouette instead of needing a separate explanation. It also helps distinguish him from a creature whose back is simply part of its body.
That is a small but practical design choice: when a character serves as a mount, the player needs to understand where the rider belongs. The red saddle makes the answer visible at a glance.
