The mental thought process tends to move away from the specific data of the senses towards abstractions that have, over time, less and less contact with the reality from which the process started. Sri Aurobindo describes the supramental thought as a process that becomes more and more immediate and real the further it progresses. This represents a major difference between mental and supramental consciousness in action.
The mind “…has to resort to a sue of the mind’s power of image if it wishes to make itself more concretely felt and seen by the soul sense and soul vision. The supramental thought, on the contrary, presents always the idea as a luminous substance of being, luminous stuff of consciousness taking significative thought form and it therefore creates no such sense of a gulf between the idea and the real as we are liable to feel in the mind, but is itself a reality, it is real-idea and the body of a reality. It has as a result, associated with it when it acts according to its own nature, a phenomenon of spiritual light other than the intellectual clarity, a great realising force and a luminous ecstasy. It is an intensely sensible vibration of being, consciousness and Ananda.”
Sri Aurobindo, The Synthesis of Yoga, Part Four: The Yoga of Self-Perfection, Chapter 22, The Supramental Thought and Knowledge, pg. 805