How do I make it so only signed-in members may see my uploaded images?
Currently, you can't, but if there's enough interest, I could make a members-only forum (that only members could see) where you could upload your pictures. If you want them to show up in posts in other forums, just copy the HTML for the picture and paste it into your post.
Alternatively, you can use another website for that.
Location: SW Idaho, USA
USDA hardiness zone: 6
Elevation: 2,260 feet Profile post