Why is the energy pyramid not a smooth geometric shape like a triangle but, rather, looks like narrow blocks stacked on top of wider blocks?

See explanation

Explanation:

As energy is transferred from one trophic level to another, energy decreases at each level, and only 10% of the energy from the previous level is transferred to the next higher level.

This is because, organisms at each level use the energy obtained from food materials for their own metabolic activities.

Hence, the energy pyramid is not a smooth geometric shape like a triangle but, rather, looks like narrow blocks stacked on top of wider blocks. Each higher level is smaller in size than the previous level because lesser energy is transferred to the next higher level.