Pictures are fun to look at, but not essential. They can be misleading as to the condition of an item (nearly everything looks better in a photo), and I'd assume that if someone is seriously looking to buy something, they already know what it looks like, pretty much.
You can always ask a seller to email or post them.
And besides, the BST forums are sort of peripheral to TFL as a whole, and from what I've seen lately, the poor ol' mods don't have time to enforce the rules in those forums as it is...
