。
Her makeup is heavy.
Literal
She [topic-は] makeup [subject-が] thick.
A textbook-clean example of the double-subject (大主語/小主語) construction: a topic 彼女は frames the broader subject, an inner subject 化粧が pinpoints the specific predicate target, and the adjective 濃い ('thick, dense, heavy') comments on the inner subject. The whole pattern produces 'as for her, makeup is heavy' — i.e., she wears heavy makeup. 濃い is also used for thick coffee, dense fog, and intense colors — a unifying sense of 'concentrated.'