Note that EBay listing states "For Parts or Not Working" !
True but probably irrelevant.
You have to look at the auction critically whether a 'scope is labelled working or not. There are a few decent vendors - kjds for instance and I'd like to think that I try to be honest about the stuff I sell but even there an item could leave intact and not work when you power it up through no fault of ours. I usually send 'scopes out with a calibration report - as much as anything so that I know I've tested everything but it takes a lot of time and the only reason I can do it at all is that I sell a fairly low volume of stuff. I don't think anyone else does this, I also check for electrical safety which, again, most sellers would probably laugh at me for despite it actually being a legal requirement in the UK.
There are also plenty dealers with low scruples around on ebay - I bought a Hameg 605 sold as "working" last year, when I received it there were so many dry joints on the board I thought it must have previously been owned by one of the temperance societies - several switches actually fell off the board when I removed the shafts to clean and lubricate them so there's no way it ever worked correctly.
Finally there are some vendors who genuinely know little about 'scopes so "working" might just mean "didn't go bang and some lights went on when I plugged it in". Of course some of the suspect vendors might try to hide behind "I don't know much about these...."
In this case the vendor probably does know little about 'scopes so is being cautious. The trace does look slightly odd but that could just be that the camera shutter only caught half of the trace. It's more significant that the 'scope isn't shown displaying any sort of waveform but there's at least a chance it's OK. It does at least appear to be able to generate a trace so some of the harder and more dangerous bits (the HT transformer and multiplier) are OK and the odds are that the CRT is OK.
If a vendor lists an item as "parts or not working" and actually says "this doesn't work" you probably know where you stand, otherwise read the listing carefully and treat everything as potentially needing some work before it is fully functional.