If you're selling something, that was never intended for private resale, the least you can do is post the pictures here. Otherwise you might as well be a scammer. The only reason you wouldn't want to share evidence of ownership is it's a fake or the condemnation will come down on you from the public.
Thanks for your opinion, although rather aggressive.
So, I have been a collectors for decades and there's plenty of other reasons why people don't share pics of their private collection with the rest of the world.
However, I am totally fine in sharing pics with people who are seriously interested in purchasing.
As anticipated, I am totally comfortable in using escrow and providing other guarantees if asked.
Best