Final answer:
The phrase in question is a metaphor, which directly compares two unlike things without using "like" or "as", in this case, comparing eyes to green apples to create vivid imagery.
Step-by-step explanation:
The literary device exemplified by the phrase "I am in love with those two green apples you call eyes" is a metaphor. A metaphor is a figure of speech that makes a direct comparison between two things that are not alike but have something in common, without using "like" or "as". In this case, the comparison is between the person's eyes and green apples, suggesting that the eyes are as fresh, vivid, or tantalizing as green apples - this is done to paint a more vivid image for the reader, without literally meaning that the eyes are apples. It differs from a simile, which would use "like" or "as" in the comparison. Similes and metaphors are both forms of figurative language, allowing authors to create strong imagery and emotional effect. An example of a simile is: "Her eyes shone like emeralds.", while a metaphor is: "Her eyes are emeralds." Both create a vivid picture, but the metaphor makes a more direct comparison.