The snow-capped Mt. Fuji is wonderfully beautiful, isn't it.

Literal

Mt. Fuji's snow-makeup [subject-が] wonderfully beautiful [agreement-ね].

雪化粧 (ゆきげしょう) literally means 'snow makeup' — a poetic compound for mountains dusted with snow. すばらしくきれい = 'wonderfully beautiful.' ね seeks agreement from the listener.