The phrase often implies drawing unwanted public attention through behavior. When he started arguing with the waiter, he really made a spectacle of himself.
Pro Tip 2/3
Negative Impression
Using this phrase suggests the person's actions leave a negative impression on others. She made a spectacle of herself at the reunion by bragging non-stop.
Pro Tip 3/3
Social Events
It's often used to describe behavior at social events where norms are expected. Everyone was dancing normally, but Mark made a spectacle of himself by doing the worm.