Very interesting. The image in that post is taken from
MoreBeer's site. I can't speak to whether they're the creator of the image, but I know the kettle that's pictured there is exactly what the actual kettle looks like, since I actually own this one.
The kettle shown in FortMillBrew's picture doesn't look like it has the extra round at the bottom, but it could just not be shown (was the kettle set on a sofa cushion?). I know my kettle (the MoreBeer one) has a more 1:1 height/width ratio, but it's a couple years old now and they may have changed it. Regardless, I really like the look of the extra height and how low the thermometer is. When I do 6 gallon batches, my thermometer doesn't even get submerged....