It often depends on the type of art that the teacher was looking for. For example, if a ceramics teacher was looking for a coil pot, often times they will just hand out a rubric. Typically the requirements on art rubrics are loose- otherwise everybody's work would end up looking identical. For example, one requirement could just be "a couple rows of different coil designs" for a coil pot for full points on that assignment. Art teachers also grade based on a self-reflection form students may fill out. For more abstract pieces, the teacher might just grade based on why the student designed their artwork like that.
Hope that helped you.
Harmony and melody, hopefully this helps :]
Negative space in painting or drawing is a space everywhere in place and between the subjects of a portrait. It may be deceptive when the space about a focus, not the subject itself customs an provocative or artistically important shape and such shape occasionally is used to artistic outcome as the physical subject of the image. Using of negative space will relief your mind to focus on the spaces and help to confound your brain – reasonably that tries to recognize the whole thing it sees.