The Tomato - or Second Reason

A good hamburger requires a nice juicy tomato,
but it's still not the most important ingredient.

The same is true of a paragraph or an essay:
The tomato is the second most important reason, cause, solution, observation, or argument.
It has to be juicy. Wilted lettuce and a limp tomato can ruin a burger,
even if they aren't the most important ingredients.
The most important part of the burger, as with the paragraph or essay, is the last one,
the meat.