Olive oil lid sealed properly?
Olive oil bottles are not sealed for health reasons. I.e., olive oil is not processed through a sterile heat canning process.

The two primary reasons for sealing the bottles are to prevent leaks and to make them tamper proof. 

The type of top in your picture is a 'Ropp Top'. It features a ring below the cap that will separate from the top when you open the bottle. This is a tamper-proof feature, as is the shrink-wrapped plastic applied over it. If the bottle had been tampered with, it would be evident and should not be purchased.

As long as your bottle has no leaks, it should be properly sealed and fine to use.