Rules on pictures?

[pookie]

What are the rules on pictures in threads? My Introducing... thread has been relegated to the Picture Gallery and I'm wondering why. I've looked through the FAQ and can't see anything relevant (may well be being blind). I know this doesn't happen to all threads with pictures...have I inadvertently broken some rule or other?

 

[JFTDWS]

generally no more than 2 pics in NL before it gets moved to PG, but it's pretty hit or miss who actually get shunted to PG

 

[rhino]

http://www.horseandhound.co.uk/forums/showthread.php?t=543365

 

[pookie]

Hmm. My thread contained two pics of my new horse and didn't 'invite other users to post pictures' Seems kind of a shame.