Mrs L B J

The initials LBJ stand for 'Little Brown Job' and is a derogatory term used by birders for any small brown bird that may be easily mistaken for any one of a number of other LBJs.

Well in this case there can be no mistaken identity.
What you are looking at is one of a mob of house sparrows that daily dodge the neighbour's cats to descend on my feeders. This is Mrs House Sparrow (Passer domesticus) resting in an elder bush after having gorged herself.