The beautiful blonde sparrow was feeding with Starlings and House Sparrows. A Golden Sparrow is a leucistic House Sparrow. Albino House Sparrows are even rarer.
A leucistic bird lacks melanin pigment due to the cells responsible for melanin production whereas an albino bird is caused by a genetic mutation causing an absence of tyrosinase in pigment cells.
If you are not sure if you are observing an albino or leucistic bird check the eyes. Albino birds eyes have pink eyes, while the eyes of leucistic birds retain pigment and are dark.