James Bond comes face to face with Blofeld in "You Only Live Twice" when he infiltrates his base in the volcano. Bond was played by Sean Connery and Blofeld was played by Donald Pleasence.
In the next film, "On Her Majesty's Secret Service", Bond (played by George Lazenby) meets Blofeld while posing as Sir Hillary. However, Blofeld doesn't recognise him.
Why doesn't he recognise him?