What it says on the tin!
If the examiner has at least 11 modified Appraise: see the approximate value of the other character's Appraise value.
Useful for merchants. Doesn't have to be exclusive to rogues, since everyone has an Examine tool now. But it could be if the DMs think it would be better that way, maybe requiring 7 rogue levels?
It would save someone having to roll a check to show how much appraise they have. Not sure if that's an issue per say, but I always feel a bit awkward doing it. Like I'm boasting or something.