This large still life study captures a thoughtful arrangement of sedimentary rocks, their natural cream, peach, and salmon tones enhanced by the cool gray background. The orange frame device draws focus to the careful stacking and interplay of the rocks' layered surfaces. The dramatic shadow cast to the right adds depth to the composition.

The title is in reference to a line in Lewis Carroll's "Allce, Through The Looking Glass" and is a reaction to the tortoise-shaped cast shadow. This is when the Mock Turtle explains why they called his teacher a tortoise, saying it was "because he taught us" - creating a pun between "tortoise" and "taught us."