Phubbing is the term for ignoring the people around you by focusing your attention on your phone.
I don't consider myself a phubber, and I use my smartphone a whole lot less than I used to when I had a day job and traveled more. However, phones (of all types - smart, dumb, house) are pretty much anathema to D-L. She considers an incoming phone call to her an intrusion, and a phone call from her as an intrusion on someone else's time. Email, Facebook, etc. - send me messages all day long. Just don't call her.
And don't pull out your smartphone in the lunch line right after one of the morning speakers put up a graphic about phubbing.
Fortunately I had to go to the bathroom after lunch, where I can multi-task. (Unfortunately, I could not get a signal, so had to wait until we got home to check 'urgent' emails.)
Oh, it didn't help either that my phone rang right in the middle of one of the morning speakers (wow, does it sound loud in a roomful of 300 people!) Or that during an afternoon speaker, my backup phone rang too (didn't know it was even on, and the ring was for the battery getting low). Too bad phones are not 'smart' enough to know when they should be silent.