Question

what is the subject pronoun that of this been left out of this conversation?

Antonela Me llamo Antonela.
Jen
Me llamo a Antonela.

a was left out. You always put an a before a name.
SraJMcGin
Not in this case. The subject is "Yo" me llamo Antonela. = literally "I call myself Antonela" but translated like: "My name is Antonela."

Sr a