Once upon a time, the OGR forum didn't have the capability to host their own photos. Many of us used Photobucket or other photo hosting sites so we could post photos here. When Photobucket went under or when members discontinued their subscriptions to these photo sites, as Rich said, all the links were lost.
OGR being able to host their own photos was one of the most important changes made to the forum. Even if you have other ways to host photos, it is best to use the OGR photo posting feature. It ensures that photos will still be visible in old posts as long as the forum exists. Moreover, you have access to the feature that allows you to click on a photo to enlarge it and get a better view of details.
Jim