I am not trying to rain on anyone's parade here, I support this Forum as much as anybody, but........
I am fortunate/unfortunate in having both a Mac and a PC in the same home, albeit two "stories" apart which with my rheumatism is a bit of a pain to switch back and forth.
On the Mac, using Safari, now the three main threads all seem to work as they did before more or less.
However, on other threads, Fenders & Skirts for example, the photo size seems to default to "thumbnail" and all photos are of that size. Same thing on other threads.
On other threads, whose names I forgot to write down, pics have now gone missing that I know were there a week or so ago.
On either machine, using Google Chrome, I have the same situation as Carnut. The "thumbnails" have now become "palm print" size and as he says once you open up the puzzle it is displayed in it's original posted size. In the case of a 3000x1200 pic, it takes up the whole screen and then some for the image.
I cannot tell you how to fix it or I would, but having been on so many Forums over the years, this is not an uncommon problem of finding and installing the proper commands and most current Forums have instruction to adapt to both the Mac and PC environments and certainly the top 5 or so most common browsers.
As regards the clearing of my cache and cookies, please, but no thanks. I belong to well over 100 sites dealing with research, the hobby, business etc.
In most all cases, I have my user name and password "saved" on the sites and I have not had to remember and type in such in some cases for years and they are not all the same and I have long ago forgotten some of them. You also lose a lot of other stuff on every site tied to that browser when you clear and clean. Been there, done that.
Please do not get angry with me as an individual here, I understand your frustrations and I am trying to be informative and as helpful as I can. But...in the end, the Forum was properly formatted/programmed before and it can be again to serve both Macs and Pcs and the most popular browsers and I hope we can get back to that situation.
With Total Respect and Support.
Bill