Last year mum also tested positive for Covid and was confined to her room. As far as I know, obviously I could not see her, carers were popping in several times a day to check on her, do regular medical checks, help with personal care etc and spent time chatting to her while there. I’m sure your dad gets more than just one visit a day, he must get more meals and drinks surely? At mums home they have an activities coordinator and during the lockdown she went and had one to one time with the isolated residents, just to chat and maybe read with them or watch tv.
We had already taken in a DVD player for mum to watch football games on so when she had Covid ( luckily very mild) we provided more dvds of other sporting events and a few films - she didn’t mind watching the same things over and over but the carers got fed up!
Mum was also still able to read so we organised delivery of her own daily newspaper for a few weeks as she was missing looking through the ones kept in the lounge.
Photos were not helpful for her without someone to look at them with her as she needed reminders of who people were and where they were taken etc. However, the home asked me to write a lengthy detailed account of all her interests and life as a child and mother so they could engage her in conversation about school, early working life, holidays etc. I added a few photos to the account to help the carers engage with mum.
I have to be honest, I don’t really know how mum coped with isolation as obviously I never saw her ( still not actually been inside the home since she moved there in April 2020!) but once our visits started again, she did not appear to have changed much.