What kind of sentence is the store clerk talked on her cell phone ignoring the long line of customers?

The sentence "The store clerk talked on her cell phone, ignoring the long line of customers" is a compound sentence. It contains two independent clauses: one about the store clerk talking on her cell phone and another about her ignoring the long line of customers. The use of the comma before "ignoring" indicates that the second clause provides additional information about the clerk's actions.