A firmly sealed bottle

A few days ago, I had to open a new bottle of soy sauce.

When I opened it, I saw this:

I have been buying this exact same brand before this, and the inner seal was one with a ring, and you pull the ring to open it. But this...no ring to pull. I tried pressing down on it but it wouldn't budge.

Have you seen this kind of seal before? If you haven't, take a little time to think about how you would have opened it... I would like to hear your ideas in the comments!

If you're done thinking... (or just don't want to think at all) what I finally did was to cut it open with a knife. I came to the conclusion that it was what the manufacturers intended us to do...because with the two different-sized circles in the middle, by cutting horizontally we could choose how big we wanted the opening to be. (I chose to make it small. If it doesn't work so well, I will make it bigger :P )

And also...I think I've seen this kind of seal somewhere. But I've forgotten where...maybe one of the bottles in my mother's kitchen?