The difference to me is the sheer level of absolute immersion in online stuff
My dh has never gamed, but he does browse Facebook/ YouTube/ news sites with such a high level of immersion that when I try to talk to him he won't react at all, and if I do drag his attention away his eyes will be darting back constantly. He agrees that he is wasting time and feels jittery and restless after an evening browsing online, but still does it
If I'm reading a good book/ watching a film/ speaking to someone I will at least acknowledge my dh arriving home. Even if I'm at a really exciting point I can still smile, nod at him, make eye contact for a second, just acknowledge his presence. If he wants to talk I can put it down. (Once I said I'd like to read to the end of the book first as I was a few pages from a cliffhanger, he brings that one occasion up every fucking time I raise the subject
)
To me that brief acknowledgement means a lot, a recognition that your partner is pleased to see you, that they have noticed you. I find it cold to come home after ten hours away to get zero reaction because my life partner is watching videos of kittens
Websites like Facebook are designed to pull your attention in and keep you browsing to up their ad revenue and share price. I don't like being manipulated by a company into acting distant from my loved ones
I don't know about 'gaming' as dh has never gamed (he used to flatshare with a gamer and watching him spend ten hours playing virtual wizards on a gorgeous sunny day has thankfully put dh off forever!) but the op said her partner was playing on his iPad so it sounds more likely it's candy crush type stuff rather than a year long campaign to capture an empire