Continuity mistake: When Peter is in the diner showing Sabrina the picture he puts the picture down and walks to get coffee. As he gets up Sabrina is reaching for the picture and the camera shows Peter asking her if she wants a doughnut. The camera pans back to her and she is reaching for the picture again - it is not in the same place it was a moment ago.
Trivia: The sinister plot of Chess Chemical, in the movie, to falsify the lab tests to show that the LDF hormone is safe to inject into cows and thus for it to get into the milk supply is based on a true story. Chess Chemical is Monsanto. LDF is the controversial "bovine growth hormone," also known as BGH. BGH was found to cause cancer in the cows that were injected. But the FDA approved it anyhow in the 1990s with its full stamp of approval.