Here’s a good article in today’s Boston Globe:
This is definitely happening at my house. 
Small household here, just two kids out on their own for years, DH who works out of state most of the month, and me.
Our Bernese Mountain Dog was such a big baby. When the kids left – and they were absolutely lovely to her! – she took it in stride. When they came back home for breaks, she sulked because they got my attention.
We have two Briards now, and they’re much more sociable. The more the merrier. Our older one was here when we had a houseful, and we could see her soak up the added companionship. Younger loves when people come, too, we just haven’t hit the high numbers (haha, nine for our small family is a lot) since he came here.
DH is in Washington DC area most of the month but telecommutes one week in four. The dogs are thrilled when he’s around and handle the changes in my level of interaction cheerfully.
Ours was very upset for the first week but he’s been better since we went down to visit her.
Our son would Skype with his cat both from boarding school and college. The cat absolutely understood that “his boy” was on that screen and would meow at him. He asked for one last Skype on the day we had to put his pet down, a year ago this month. :((
First morning my child was home from college for the summer, I couldn’t find the dog. I know she came down with me…quietly I walked upstairs. Their she was curled up outside a closed door waiting for her BFF to wake up and say hello.
Okay, well, that is just sad as hell. 
I guess it’s good he got to say goodbye, but that just brings a lump to my throat.
None of our dogs have ever reacted to visuals on a screen. I don’t think they actually see those pictures as anything in particular. But our cat – at least our current one – absolutely watches and reacts to what is on a TV or computer screen. You can see her eyes following the action, especially if there’s an animal there. I can believe that she might recognize me over Skype.
Just be careful if you get a new dog while your kid is at college.
My mother and stepfather did this. They got a new puppy while I was away, and it slept in the kitchen, with a gate across the doorway. It would not allow me to get past that gate. I mean truly would not allow it. (The dog was a Doberman.) It considered me a stranger and treated me accordingly.
If I wanted a snack or drink at night and there was no resident family member available to restrain the dog, I would have to drive to McDonalds.
My dog doesn’t get FaceTime either and honestly it seems to upset him that he can hear his girl’s voice but can’t find her
Our cat loved to play the Friskies “fishing” game on my iPad:
https://www.youtube.com/watch?v=Bq7yC2g5Hfs
He was very eye/paw coordinated and was a high-scorer. Cats definitely see what’s on the screen.
My cat loves to watch tennis on TV, if only to follow the ball. I’m not sure he had any opinion on Serena Williams’ tantrum. But as far as Skype goes, he ignores me. But then he ignores me in person, at least until it’s time for food or bed. 
The dog, however, does respond on Skype, but I think it’s the voice more than the image.
We usually do phone calls with the children. We did weekly Skype with our daughter when she was on a semester abroad. Our dog was totally crazy. Licking and kissing the screen. Talking with a yip and a yap. She is a small dog so I could tuck her under my arm for future calls.
Our dogs definitely enter the room when DS FaceTimes…but they never look at the screen…their ears just perk up to his voice and they plop down nearby. I’ve found them napping in DSs room many a time when he’s gone, but they rarely go in there when he’s home…
My childhood cat would avoid my room until a day or two until I came home from college. Then he would start sleeping on my bed again.
I had to go home my first weekend at college, and the second as well, because my dog would not eat. He spent all of his time on my bed. Finally he learned that I would come back. Sometimes and got over it.
When my oldest daughter came home on breaks our dog would immediately run to his food bowl and bark to remind her that it was her job to feed him. Didn’t matter what time of day she came home, he just wanted to let her know her place. It had been her job in high school years.
Ahh… feeding. Our calico cat grieved herself to death. She just stopped eating. She only ate dry kibble that kiddo poured into her dish. Neither Mr. nor I could do this for her. She simply refused to eat… we had to take her to the vet to get her IV fluids… she became lethargic and just passed away. Apparently, it can happen with cats. So keep an eye on your furry family members whose humans went to college.
Omg. @BunsenBurner that is awful.