I asked the same question a while back and here is what I was told. It worked!
1. Post or start a new thread.
2. Click additional options.
3. Click automatically parse.
4. Click manage attachment.
5. Click add to file.
6. Select photo (s) from computer hard drive (picture file).
7. Click DONE if the photo has a check mark.
8. Add comment and post.

Maybe someone else has a better way, but this method worked.