Fuel Gauge mystery (wrong forum :-)

[visualexport]

Greetings, I know its clearly the wrong forum... BUT

Take a look at this Cessna 172N gauge maxing out at 24,
The usable fuel is 25 US gallon (according to POH)

What are the two white lines? Just an eyecatcher? Or is one indicating 24 gallon and the other 140lbs? if yes, which one?
And where is the 25 gallon mark? When the needle touches the F ?

I know its useless details... but still... its haunting me ;-)

Thanks in advance for any light.

 

[Tweety]

 

[zoomy350]

 

[visualexport]

 

[GM.]

 

[Lon]

 

[Ed Dartford]

 

[Spert]

 

[kshaw]

 

[kju1pitt]