Here's why:
* Appositives are words or phrases that rename or explain a noun or pronoun. They usually follow the noun or pronoun they describe and are set off by commas.
* In this sentence, "Snow Fall" is the noun being described, and "my favorite" is an adjective phrase that modifies it.
Example of an Appositive:
"My favorite poem, Snow Fall, is beautiful."
In this example, "Snow Fall" is the appositive because it renames the noun "poem."