Schematically, yes.
However, the ones which hypnotized me didn't resemble the "jelly jar as seen from below" shape in your diagram.
The ones at the Esso station were 4" wide and 2" tall. The corners was rounded.
They were pudgy half knockwursts (as if split down the middle).
The whole 'sight glass' thing was a throwback to the days when such a portal assured the buyer that fuel was actually being delivered.
Hey, if fuel stations still had the hand crank delivery systems with fuel pumped up to a calibrated tank then released to the vehicle, there'd be less unemployment.