It really depends: Pictures are resized to display in 1024 width max. If a contact sheet is organized well (e.g. the numbers I've given) the result are thumbnail pictures on the contact-sheet bigger than many single pictures uploaded.
an example:
https://www.gaytorrent.ru/showpic.php?pic=1940427&win=popup
another:
https://www.gaytorrent.ru/showpic.php?pic=1944613&win=popup