But you haven't even tried!
That last clue was HUGE. Look, I'll help you one step further: the screencap I posted in the other thread was from "O Brother Where Art Thou", but you should already know that because it was correctly answered.
So, now you know that the lead character in this mystery film is a movie director who wants to make "O Brother Where Art Thou".
If you still have no idea or don't want to ask any more questions I'll post the answer...