Comment by RockofStrength

This is already incorporated to some extent. Keeping in mind sets vary,

Knight's profile is the L-shape.

Rook has four parapets (and four gaps).

Bishop has a diagonal slit.

King has 8 stubby protrusions in his crown.

Queen has 8 pointy protrusions in her crown.

Pawns are most basic (ironic considering their qualities are most byzantine). I guess it's nice to have a baseline piece for aesthetics.