I'm of the opinion that it is not. Wittgenstein and Hitler did attend the same school in Linz but the photo is dated to a time when Wittgenstein might not have been at the school. Also Hitler and Wittgenstein would have been two grades apart, which would make it odd for them to appear together in what appears to be a class photo.

You may or may not be aware that Wittgenstein and Hitler possibly knowing each other in school was the subject of a book, "The Jew of Linz". The link below covers the photo and the arguments for and against it being Wittgenstein in the same photo:

http://en.wikipedia.org/wiki/The_Jew_of_Linz#Realschule

The argument in favour seems to be the author's claim that he had the photo checked out by Australian state police and they agreed. I haven't read the book but I express doubt that it is quite as straight forward as that. I've worked in the Victorian public service and I doubt the Police would do a 'job' for an author, I'm not even sure they would have assisted if they had been asked by a university - it would have to have come from the government. Also I'm reluctant to believe that there was a dedicated photographic analysis unit, I think that would fall under more generalist forensics units rather than having one unit that does nothing but analyse photos. What I'm getting at is made whoever looked at this photo wasn't quite the master/expert the author claims.