Transitive verbs are verbs that have subjects or objects that receive the action. They are either active voice -- where the verb has a direct object -- or passive voice -- where the direct object is actually the subject. Active is always preferred over passive. In the first tweet, the verb "moisten" has a direct object, i.e. Courtney's heavily frosted mouth. In the second tweet, however, the direct object -- "morning" -- has become the grammatical subject so the transitive verb -- "has been" -- is in the passive voice. The same message could have been conveyed in an active voice: "It has been a breathtaking morning."