I was posting some information about "The Pushpin Project" and I noticed vBulletin shrunk down the image attachment I had made.
The Pushpin Project
It shrunk it quite a bit and I was a little annoyed, so I raised all the image attachment limits. The height and width were increased to 6200 and 2400 pixels respectively and the effective maximum file size is not about 2 MB, this ends up bumping up against PHP's own maximum upload size.
Also, the zip, pdf, and txt file limits were raised to 2 MB and the vBulletin will now try to create a thumbnail of all image attachments.
So start posting images! (until my account runs out of disk space