6 only fit on a 1280 wide monitor like mine. A 1024 monitor could only hold 4.
Nobody would open spoiler boxes.
A scrolling GIF-type thing would have to be newly generated for each player, which would take up a lot of space on the server.
Choosing medals might be nice, but why choose when you can...
Add a fourth row, allowing 16 unique medals. It wouldn't really make posts that long. Not that often do the medals reach the bottom of the post, past the signature, etc. I've thought of lots of options, and this is the best one imo.
![Smile :)](./images/smilies/icon_e_smile.gif)