Is there any real debate on Facebook made on such a topic?

Your photo shows a girl who is definitely ‘beckoning’. I have noticed something that says. Your use of the word “beckon” is correct.

Beckon is a specific gesture. Can a signal mean a million hand gestures? So beckon is a specific act while signalling can mean anything.

Is the word nearby incorrect? What do you

do when you see Alex beckoning Sam into your room?

If you mean closer than he already is, how

do you say this?