The value of the art in question lies in the practical benefits one gains from it.
Obviously made for a specific purpose.
Does it mean that paintings and literary works can never have any function?
The personal functions of art are varied and highly subjective.
A function depends on the artist who created the art.
An artist may create an art out of self-expression, entertainment, or therapeutic purpose.
Art is considered to have a social function if and when it addresses a particular collective interest as opposed to a personal interest.
Art may convey message of protest, contestation, or whatever message the artist intends his work to carry.
Political art is a very common example of an art with a social function.
Art can also depict social conditions such as photography (pictures of poverty).
Performance art like plays or satires can also rouse emotions and rally people toward a particular end.