Here is the mark of a true seeker. Arjuna does not say 'Show me.' He says, 'If you think it is possible for me to see it, O Lord of Yoga, then please reveal your imperishable Self.' The entire weight of the request rests on Krishna's judgment, not Arjuna's desire.
It is like a child asking a parent to take them to the summit of a mountain — not insisting, but trusting the parent to know whether the child is ready for the climb. Arjuna is aware that what he is asking for may be beyond mortal capacity. So he leaves it in Krishna's hands.
The name Arjuna chooses here — Yogeshvara, Lord of all Yoga — is significant. He is saying: you are the master of every power, every capacity. If anyone can make this vision possible, it is you. And if you decide I am not ready, I accept that too.