The set of filename extensions matched by the filter regular expressions
Plugins.Extensions.FileCommander.plugin is considerably smaller than the set of music, picture and movie extensions in
Components.FileList.EXTENSIONS, which are used to select the
FileCommander's icons for the file type. For example, the extension "ogm" will have a "movie" icon, but won't be accepted by the "movie" filter expression.
The filter regular expressions also don't have a
$ end-of-string match, so that the RE that would match the "iso" extension would also match "isobar" or "isolated", and the extension match for "jpeg" is redundant, because it would be matched by "jpe".
Best checked by examining the code.