I know there must be a reason. Why not just post images full size? Seems like a lot of extra click for those that wish to see the image.
I've been sayin' the same thing since day one of this software upgrade Larry. Peter allows us to post much larger files so why not capitalize on that privilege? Thumbnails serve no purpose when it comes to looking at the details on a coin. Many photos posted in larger formats can be 'blown up' for easy viewing........
Could be any number of reasons, but I suspect the primary reason is because thumbnails are the default.
Well, if you're on a slow connection, the thumbnails load a lot faster. And if you're on a metered connection, it's good to be able to choose whether you want the large image. But in either case, it really ought to be under your control as you're viewing the page, not under the poster's control when making the post.
I'm on an average DSL connection at home. With a thumbnail, I click on it and wait for it to load. To see the larger image I have to click again and it opens in a new window. I now have to click again to close that window. Next I have to close the thumbnail to get back to the thread. I'm not saying that's a lot of work but it is a bit slow.
I right click the name of the thumbnail and tell it to open in a new tab. I look at it and can either switch back to the original tab or close the new tab and I am right back in the thread.