적히다 is the passive of 적다 "write down", so 라고 적혀 있다 means "it has such-and-such written on it". Every line here is someone reading text off a physical object — a jacket, a bun, a mirror, a slip of paper: 'M.코바야시'라고 적혀있어요 "it says M. Kobayashi", 혹시 거울에 뭐라고 적혀 있으세요? "what does it say on your mirror?". 적혀져 있다 also appears and means the same, though it doubles the passive marking. Its broader cousin is 라고 되어 있다, which covers signs and listings too.