The supermind has its basis in unity and infinity, while the mind is based in fragmentation and limitation. The supermind knows wholly while the mind tries to piece together knowledge from disparate facts, ideas, and thoughts.
Sri Aurobindo observes: “The supermind can do all that the mind does, present and combine details and what might be called aspects or subordinate wholes, but it does it in a different way and on another basis. It does not like the mind bring in the element of deviation, false extension and imposed error, but even when it gives a partial knowledge, gives it in a firm and exact light, and always there is behind implied or opened to the consciousness the essential truth on which the details and subordinate wholes or aspects depend.”
As we see the mind has the power to create representations of real things and present these representations, it should be noted that this power originates from the supermind, albeit there in a form that does not create “stick-figure” type representations, but real and full-bodied representations. “There is such an infinite power of representation of the supermind and that is the divine power of which the mental action is a sort of fallen representative. This representative supermind has a lower action in what I have called the supramental reason, nearest to the mental and into which the mental can most easily be taken up, and a higher action in the integral supermind that sees all things in the unity and infinity of the divine consciousness and self-existence. But on whatever level, it is a different thing from the corresponding mental action, direct, luminous, secure. The whole inferiority of the mind comes from its being the action of the soul after it has falled into the nescience and the ignorance and is trying to get back to self-knowledge but doing it still on the basis of the nescience and the ignorance. The mind is the ignorance attempting to know or it is the ignorance receiving a derivative knowledge: it is the action of Avidya. The supermind is always the disclosure of an inherent and self-existent knowledge; it is the action of Vidya.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 22, The Supramental Thought and Knowledge, pp. 797-798