Are you trying to upload from a Mac? It took some experiment and Rube Goldberg would be proud but after tinkering I found a way that is working.
1. Go to the home page and click on Freight Sheds even if you don't have one.
2. Sign on using your sign in for LSC.
3. Have your edited and resized picture on your desktop.
4. When you go to browse in LSC you should be able to look under desktop and find the picture.
5. Open it and click on upload and a copy should show up in LSC.
6. Click on that and it should open in a url. Cut and paste that address in the forum note.
7. This is working for me. It sounds like more work than it is. If it's "grumpy" send me an email and we'll figure it out.
8. DON'T try to use My Files directly from a note to the list. It won't work, at least it doesn't for me.
9. When you return to the list you won't see a picture list. Double-click om forumfiles and the list will come back.
I’ll leave this in Website for now until we make sure it works for all Mac users. After that I’ll move it to articles. Let me know if it works on your Mac or if you find an easier way to do it.