The most outstanding metaphor is "the cherry hung with snow." what two basically unlike things are being compared? why is the metaphor effective?

The line "the cherry hung with snow" actually depicts the comparison of spring and winter. This results from interpreting "snow" in the last line to be a metaphor for the cherry blossoms. Although the interpretation is not impossible, the poem’s realization is greater if "snow" is meant literally. Thus, the speaker or author solves a problem: rather than having to look at the cherry wearing white fifty more times, he doubles his opportunities.