。
She is as beautiful as Snow White.
Literal
She [topic-は] Snow-White [like-のように] beautiful.
~のように builds a simile from a noun: 'like X,' 'as X.' Combined with an adjective like 美しい, it gives 'beautiful like X.' 白雪姫 ('Snow White') is the standard Japanese name for the Disney/Grimm fairy tale character — a familiar shorthand for archetypal beauty.