In this causative construction, the verb is a transitive verb whose direct object is marked by を.
Unlike the causative construction 1-1 in which the causee(i.e., Y, or the person who actually performs the action) is marked by を, the causee here is marked by に.
社長は社員に電話を かけさせました。
The president [of the company] made an employee make a telephone call.
父は妹に新聞を 持って来させました。
My father made my younger sister bring the newspaper.