Open the app, start a Capption, and upload any image.
If the spinner in the upper left corner is spinning, media is still uploading,
Wait till the spinner is gone to complete the Capption.
You can check the progress by hitting the menu icon in the upper left corner.
On the lower half, a progress bar is shown.
Don't see this bar? Good news! All the media is uploaded correctly.
\
If you followed these steps and the photos are not shown in the PDF report.
Follow the steps in this article