Could be for a couple of reasons I can think of.

(1) One is if you select media type or any of the filters on the left of the LW window then it will only display those type. eg: 3 video files compared to 814 other types of files.

(2) The other files might be getting filtered out via Junk filter. If you wish to display the junk results, go to Tools > Options > Filters > Junk, & choose your option. Personallly I choose show at bottom of search results. You may find you need to ease up the strength of your junk filter or retrain it.