Item description:

This will unlock the Sightseer achievement in bioshock infinite, this is the achievement you obtain by viewing all of the kinetoscopes and telescopes in the game.

It also pops a couple of difficulty achievements amongst others

In order to obtain the achievement, simply make your way past the enemies and into the next area, enter the "Where we learn area" and go through the smashed window at the back. Once through go straight ahead and look to your right and there will be a kinetoscope, and look into it.