WARNING: MAY NOT BE CORRECT
Comparisons in poems are when you take two very unlike things and compare then. e.g. the tissue is as white as a polar bear. Here are some examples.

The grass is green as a frog.
The ground is brown as a turkey.
The telephone is black as black hair.
The sun is yellow as a pencil.

-Daisyah

The grass is green
like a lily pad.
The vegetables are
tasty as candy.
The tiara is shiny
as a king’s throne.
The moon is a shiny
silver ribbon.

-Rainbow