Showtime reflecting upon a crack in the sidewalk that he caused by almost consuming a koopa troopa shell. The yoshi needs to remember to be careful, especially since he lives along the San Andreas Fault.
Those who remember the original Super Mario World game may remember that yoshis get certain abilities by holding koopa shells in their mouths, depending on the shell color and yoshi color. Yellow yoshis make mini earthquakes when they land on the ground, no matter what the koopa shell color.
The Hollywood background was the idea of darkdraconis and my own, to indirectly point out the fault.