A crucial moment. Krishna pauses before revealing the vision and tells Arjuna plainly: "You cannot see me with these ordinary eyes of yours. So I give you divine sight. Now behold my sovereign yogic power." The gift comes before the vision, because without it, the vision is impossible.
This is not a limitation of Arjuna's devotion or worthiness. It is a limitation of human perception itself. A radio tuned to one frequency cannot pick up another, no matter how powerful the broadcast. The eyes that see the battlefield, the dust, the chariots — those eyes operate at one frequency. The cosmic form operates at another entirely. Krishna is, in effect, upgrading the receiver.
There is deep compassion in this act. Arjuna asked to see, and Krishna does not simply show. He first equips Arjuna with the capacity to bear what he is about to witness. The teacher prepares the student before opening the door.