It is very common for users not to understand how to upload a picture. One the reasons might be that if you search in help for picture you get no results. If you are willing to search for image the first result is about flair, the second is about chat rooms and the third result is about formatting your posts.
These search results are not very helpful.
Can we get redirect or link for "picture" which is a more common usage than "image".
It would be even better to have a separate help item for how to upload a picture. Perhaps it could have pictures? And mention the upload size limit?