To make fun of the manner the writer is criticizing. It has a very sarcastic tone to it.
A. Reports by the U.S. Department of Agriculture
An example of a simile is the following:
"The tree was as thin as a hound dog."
As in the sentence above, a simile is a figure of speech which compares two different things, in order to make the description more intense or forceful. Another example could be:
"The man is as tall as a giraffe."