A lot of sites seem to have a few quirks; at least all the sites which I use.
WAB is a bit different when it comes to uploading images, until you get use to the system.
NUK is certainly a bit strange when it comes to starting new threads. You have to decide on the initial starting point after searching to see if there is already a current thread on a similar subject. But once you decide where you are going to post the topic it becomes quite straight forward.
I usually link images from my P base galleries but here on WAB you have to go through the upload procedure from an image on your computer hard drive.