No interactions present.
that's what I thought looks like a blackbird also.
this sort of leucism seems quite common in blackbirds. Apart from possibly making them stand out to predators, it seems to have no ill effects.
Sometimes it appears to persist from year to year, in other cases what appears to be the same bird (based on habits or other features) may show white areas after a moult.
To human eyes it can seem quite beautiful, and it certainly helps working out what individual birds are doing!
I assume it's genetic, but have no knowledge of that.
Lat/Lng: 50.9339, -0.1796
OS grid ref: TQ280165
In a large garden by countryside.