The element of satire that makes something seem less important that it really is, is:
UNDERSTATEMENT
There are several elements of satire like exaggeration, parody, diminution, ridicule, sarcasm, etc. However, an understatement can make something important be seen as small or trivial.
An example of an understatement:
*if there is a hurricane* saying: "it has been a little rainy lately"
