I think the issue arose because in the post in question, you said:
Heres an example of the sort of thing I would want to do

and the picture)
From that, in the context of the thread, people assumed you were showing an example of what someone else achieved, but which you aspired to. I don't think the problem is with the account, rather it's with how you phrased your post. Now, if you'd said something like "Here's where I need to be able to use . . ." along with the picture, it might have been less confusing. As it is, somebody thought you'd posted an example of a photo you found somewhere that apparently did what you hoped to achieve.
And no, making it clear that the photo is hosted on your own gallery wouldn't resolve that particular doubt. People have copied images and put them up on their own sites so they could post "How do I. . . " shots before.