[Seven Skins]

This hack does not work in albums, please read the info ...

This hack resizes external images (not attachments) in cms, blogs, posts, new thread preview, signatures, private messages, visitor messages and vBadvanced CMPS.

Try adding the code below in the additional CSS.

#picturelink img {
width: 100%;
}

If this doesnot work try this.

#picturelink img {
max-width: 800px;
}