Answer:
I would say that the word missing from this sentence would be skip.
Explanation:
In order to complete the last sentence, and to complete it with a word that would match the whole message the author wants to communicate in these lines, I would pick the word skip. I chose this word because Gila uses a nonverbal communication to be understood by Henry, but does it with an expression that will be very clear for the receptor and needs no words. Gila replaces the words (verbal communication) with body signs. Gila does that sign with the fingers in order to omit/skip verbal communication and be understood by the receptor of the message anyways.