I don’t think magpies care about the pigeon, but in this case they do care about the bird of pray taking liberties in their back yard.
Corvids, like magpies, crows and ravens, will regularly birds of pray, like owls and hawks if they come into their territory.
They will also try to steal their food by distracting them and pulling them by the tails. Crows and ravens even do this to foxes and wolves sometimes, but that’s a higher stakes game.
Magpies are pretty smart, whenever our local fox turns up for a snack you can be sure the magpies will appear within seconds, They know we put out foxy snacks and are determined to share his spoils. one gets behind and pecks foxy’s tail, when he turns around the second magpie dives in and steal some food.
