The figure of speech you're describing is called a simile. A simile directly compares two different things by using connecting words such as "like" or "as" to highlight a particular quality or characteristic. This comparison helps to make descriptions more vivid or emphatic. For example, in the simile "as brave as a lion," the bravery of a person is compared to the known bravery of a lion, enhancing the description of the person.

Similes are a common literary device used to add color and depth to writing by drawing unexpected or imaginative comparisons.