Final answer:
In a phone message, the only cue from a face-to-face conversation that can be included is the vocal tone, which conveys emotions and aids in understanding the message.
Step-by-step explanation:
An important component of a face-to-face conversation is nonverbal cues, which include eye contact, body positioning, facial expressions, and gestural communication. However, when the interaction is not in person, such as during a phone message, many of these cues are lost. The only cue from a face-to-face conversation that can be included in a phone message is the vocal tone. Vocal tone can suggest a speaker's emotions or attitudes and can create engagement with the audience, aiding in the comprehension of the message.