[quote saraclara]@SarahAndQuack, OP wasn't interfering with her DD's parenting by trying to engage her DGS in a game. That's just a ridiculous claim on your part.
My toddler DGD barely seems to any fruit and veg at home, Her diet is more carbohydrate and sugar-heavy than I'm comfortable with. I make sure she has at least some veg with her lunch and a fruit snack (as well as a biscuit later) when I do her childcare. That's not interfering, that's just feeding her what I fed my own DDs.
But I have never said anything about her diet to my daughter. Because that would be interfering.[/quote]
I think there is a very big difference between doing things differently with no commentary (which you're describing), and consciously being 'stricter,' which implies some kind of actual interaction about rules.
If your grandchild eats more veg and fruit with you, fabulous. FWIW my DD eats more veg if I make her lunch than if my partner does, because DD has always seen me eating more fruit and veg than my partner does, so it just seems natural to her. She doesn't question it.
But I do think you run into issues when a child gets the message 'granny has a different rule from mummy, granny thinks mummy is not strict enough'.
To me, the OP's description sounds like the latter, in part because she's several times mentioned trying to distract the child from his screen - she's not talking about just wanting to interact, she's talking about wanting to interact because she disapproves of what he's doing.