Final answer:
The line containing the metaphor is "Plushy trails, like dreams, unfold," as it compares 'plushy trails' to 'dreams' in a non-literal sense, suggesting comfort and seamless motion.
Step-by-step explanation:
The line "Plushy trails, like dreams, unfold" from Like Trains of Cars on Tracks of Plush contains a metaphor. A metaphor is a figure of speech in which a word or phrase is applied to an object or action to which it is not literally applicable. In this line, the plushy trails are compared to dreams unfolding, implying a sense of comfort, smoothness, and the fluid movement of dreams. The use of 'like' indicates a comparison, suggesting that the trails are as intangible and mesmerizing as dreams, which creates a vivid mental image for the reader.