I suspect the O has simply been removed, from the 2014 and earlier options; the larger
were available back when this set was first referred to (
https://forum.oneclickchicks.com/show...&postcount=110 , regrettably without linking info); while now, when using the trick I outline below, all you get is the 3X size...
Back when I posted some from the set simonlintworm so helpfully pointed us to (cf.
https://forum.oneclickchicks.com/show...2&postcount=64 and his quoted post), what I did was as follows:
1) Get the source info for an example (in IE, pulldown "View" then "Source"); sample url garyw90617.smugmug.com/Other/Fremont-Solstice-Parade-Naked/i-c8C3qhh/0/M/DSC_0488-M.jpg
2) Get one you want to save in the large window, as at garyw90617.smugmug.com/Other/Fremont-Solstice-Parade-Naked/42729430_jPFMJf#!i=3366849517&k=bTxvP5T
3) from that url, substitute the picture-specific code
bTxvP5T for the part in 1) after "i-" (i.e. remove "c8C3qhh" and paste in "bTxvP5T"), change the size designator (the "M" between "0/" and "/DSC") to what you want, in this case O, and finally simply remove the "-M" just before ".jpg"
4) Go to that url, and save result
Oh, and P.S.: these below are from the set linked in 2), where you may apply this technique for any others you'd like...