I am a Photography student currently studying at a local TAFE course in Photo Imaging. I had created this account for the soul-purpose of being able to upload and share my course work with friends, family and anyone else that would care to see.
If you see this icon on any of my photographs, it means that I am allowing you to take the photo, edit it, do what you want. As long as you give me credit somehow for taking the photo.
If you see this icon on any of my photographs, it means that I am not giving anyone permission to take, edit or copy it in any way, shape or form.
You may be looking at those icons and wondering to yourself, 'Well why not just choose one and use that for all your photographs?'
My answer to that is; I am particular about my photographs. If I feel completely accomplished and proud of a photograph I am likely going to want to keep it to myself, I don't want someone else damaging something that I care completely about. If it's a standard, 'I could take it at anytime' photograph, I don't mind if people are to use it seeing as how it's likely not original and can be duplicated within someone else's camera anyway.