It holds your base plate so it can be raised or lowered. In your picture the floor is lowered, it seems the device is not installed correctly if you have any challenges.

There are some videos on youtube, just Google

 

Thanks, so its only purpose is to stop the floor bending in the high position with lots of weight on it, so I can happily stick it in the garage and forget about it, then the carpet will fit properly in the low position.