That is most likely a photo of a Tesla/Oudin coil exciting the gas to show the tube is gas intact. Normally the gas reservoir does not glow. In a way, its a good sign. There are no electrodes on the gas reservoir, so in normal (or even in Abnormal!) operation there is no way for the power supply to make it glow.
The picture does not show the orange glow of nitrogen, so there is a strong chance (>96%) the gas mixture is pure. Hard to tell from a photo, but that looks just like a normal gas mix glow.
Just because it has gas, does not mean it will lase. But it is a re-assuring sign to see the picture.
I'd ask the seller if he used a coil to take the picture.
Steve
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...