If you're checking the sight glass just after having put the bike on the stand after a ride, oil will be running down it from the cylinders / head and make it look as if the oil level is full. It can take a good few minutes for the oil to drain down into the sump and filter which is why the general advice is to check the oil level on the centre stand with a warm engine after the bike has been allowed to stand for 10 minutes.
The only reason this wouldn't happen on another bike is if the layout of the sump had some kind of well next to the sight glass, otherwise as DekF said it's not possible for a liquid to ignore physics or gravity.
The only reason this wouldn't happen on another bike is if the layout of the sump had some kind of well next to the sight glass, otherwise as DekF said it's not possible for a liquid to ignore physics or gravity.