Hi Tammy,
we have identified this issue already and are investigating it. We have seen different behaviours with different browsers. Seems there is a JS issue, where the button doesn't get enabled once you have selected a picture from the browse selector. It is currently unclear where this comes from as we don't see the same behaviour on our QA instance. I've opened ticket COMM-3033 for this and added it to the SCN Known Issues List.
We hope to have it fixed as soon as possible.
Best,
Oliver