Le quedan bien esos zapatos - Those shoes suit/fit him/her well. Les quedan bien esos zapatos - Those shoes suit/fit them well. Quedar is the verb Le is an indirect object pronoun. Quedar can also be used for "to remain" - the sentence "Quedan esos zapatos" would mean those shoes remain. Perhaps the indirect object pronoun is being used here to signal to relevant usage of the verb.