Not sure if it was the first time that we see the hatch (its pretty uncovered, so I don't think this is the first), but no one specifically sees the numbers - the camera pans in on the numbers, amongst darkness and climatic music.
(I'm re-watching it right now).
By the way, now that I see Locke working with Claire, building the cradle/traps/etc., I'm getting pretty suspicious that Locke had something to do with Claire's abduction. I have a feeling that he might be one of the "others".