In simple terms, an art consultant is like a financial planner or a private banker of arts. However, it sounds more like an expert of art collection investor.
Art collections combine the features of numbers and pictures like coins, so providing peofessional knowledge, like museum attendants, is also one of the art consultants' important jobs.

Stated other way, art consultants have high degree of professionalism in the works of art. They can also provide many-sided advices from the customer viewpoint. That is art concultants.

・High-professional staff in the works of art
・Providing high-exertized knowledge from the customer viewpoint
・Providing pointed advice about investment
・Providing pointed advice about promotion