Tolkien was in his mid-seventies at the time of this production; but most of the 'faces' being interviewed were young Oxford students, aged around twenty years. What was extraordinary was how animated this old-man Tolkien was - how mobile and expressive his face; and how much more so than the faces of the young people.
Tolkien is extremely engaged by his environment, alert to the surroundings and the interview situation; his face showing what he feels from moment to moment, with sudden changes in emotion very obvious, and quick smiles, laughs and an impish humour.
Tolkien comes across as exceptionally alive and open, quick-witted, unselfconscious, unguarded and spontaneous - especially considering that he knew he was being filmed and recorded for television.
What I want to emphasise is how unusual this is; what an unusual man Tolkien was. This ought not to be any kind of surprise, because geniuses always are unusual people - one way or another. And how his personality, his nature, was - of course - exactly what was needed to write what he did.
There seems to be no barrier between Tolkien's emotional life and its expression; many of the other people interviewed have faces like masks; there is a public persona, and the inner life is both shielded and blocked.
This perhaps needs emphasising in light of the impression from Humphrey Carpenter's official biography that Tolkien's external life (after the First World War) was dull and uneventful... Well, that clearly did not apply to Tolkien's own experience of his life. We can see this.
What is clear from watching Tolkien is that his moment-by-moment response to being-alive was - at least sometimes, and probably even more so when young than in here in his twilight years - one of tremendous vividness, and power.