Usually it's done by making a non-looping animated image with two frames, so the first becomes the thumbnail, but I don't see a flicker while loading this one. Opening it in Gimp and IrfanView gives the thumbnail image, though, so it may be.
There are ways to alter thumbnails included in the file (and even use images as file archives), but since Danbooru generates its own thumbnails, I don't think it'd fall for that.
Alguien said: I am missing something because i dont get it how is "thumbnail surprise"?
The thumbnail is regular Keine, the full sized image is EX-Keine. If your browser supports whatever was done here.
Co250 said: Hmmm... Chrome, Firefox, Internet explorer, none of them works. God must be hating me..
Do you look at the full image or a resized one? Only full seems to work, try clicking the image size under statistics to make sure you have the right one.
Schrobby said: Do you look at the full image or a resized one? Only full seems to work, try clicking the image size under statistics to make sure you have the right one.
I did, but nothing happened, strange because other thumbnail surprise images works perfectly fine for me
Didn't work for me using Google Chrome, but it does work for Firefox, my account is set to display full size by default, so maybe that's why? I wasn't signed in on Firefox.
(Also, it's been a long time, but Danbooru keeps saying "Error: Hourly Limit Exceeded" even though I haven't posted in a day...)
Since it's a PNG, it probably has something to do with subtley shifting the perception of color by having just enough pixels in the exact right location to give off a different color when compressed. say it's compressed 6x, that means only 1 in 36 pixels have to have normal Keine's colors in it. Since the color shift is subtle enough, you don't pick up on those small number of pixels when viewed at full-size.