I am not sure what it is an indication of. I have sent a link to the picture to the GoPro people along with what another issue I am having with my camera. Hope someone from customer service can let me know what it means.
Buried in the manual, in the section called "Important Warning Messages" is the File Repair Icon. Which means you had a corrupted video file during the recording. After pushing any button, the camera will attempt to repair the file.