It is a conscious decision to not show everything but restrict it to video, audio and image files because we do not strive to be a finder replacement but a tool focused on certain types of media files. We know this is a grey area and that in some cases it would be nice to also see project-related (e.g. word) document, so we may revisit that in the future but not likely very soon, so don't hold your breath.
However, if you run into a certain video, audio or image file type, we do not display, please report this and in most cases we will try to fix it.