There is disclosed a brush seal assembly including at least one annular bristle pack. The at least one annular bristle pack extends circumferentially around a central axis of the brush seal assembly. The at least one annular bristle pack has bristles extending along longitudinal axes from roots to free tips. The bristles extend toward a cylindrical plane of a the seal land. Projections of the free tips on the cylindrical plane define a bristle tip projection surface being non-axisymmetric. A method of operating a brush seal assembly is also disclosed.