I think he might be getting to hot as she puts him in a sort of a sleeping bag without arms. She also has put black paper on the windows so the poor child is in complete darkness all the time, apprently her Mother's idea.I would like him to get use to sleeping in the daylight like my son use too
I thought you had a good point at first (regarding the swaddling for an 8 month old). But those 'sleeping bags without arms' are the most commonly used baby sleepwear at the moment. They have different tog ratings (from 0.5-3.5) depending on room temperature and come with (or you can google) a chart explaining what the baby should wear depending on room temp and tog rating. So the sleeping bags are perfectly fine and I doubt he's getting to hot, I'm sure his mom is capable of checking he's in the right one. Also, they're far safer than blankets.
I also have DD sleeping in a pitch black room in the day (we have a blackout blind). She naps far better like that and is much happier and well rested for it. As well as sleeping 12 hours at night. As for I would like him to get used to sleeping in the daylight like my son used to, not to be harsh but he's not your son. You had your turn at parenting, now it's your sons and DILs. They will do things differently to you, it's not your place to determine how THEIR son should be raised. Also, you seem to be blaming all of this on your DIL but your son is also his parent.
And apprently her Mother's idea this makes you sound quite dismissive of her mothers suggestion. Why? She raised your DIL after all, she's just as much of a parent as you are. Your way of raising a child may have been different to hers but that doesn't make it better. And if sleeping in a dark room helps your grandson sleep better then surely that's a good thing. It sounds a bit as if you may be jealous of her mom to be honest, and don't like that she's taken her mothers advice.