Identify the first names of the movie stars.
The first names of each movie star pair with a “-ing” word clued at the bottom of the page to make a movie title.
Taking the letters in the red starred positions, and filling in the blanks below the images in order, gives SIGN HACK : NERD ????. Some knowledge of MIT hacking lore (or just googling “sign hack nerd”) reveals that the four-letter word completing that phrase (and fitting the puzzle theme) is XING, the answer.