Presently, no alerts is triggered when a Photo, File, Sound or Video is edited. Please see solution below :
In inc\classes\BxDolFilesModule.php
Find :
if ($this->_oDb->updateData($iFileId, $aValues)) {
Just below, Add :
bx_import ('BxDolAlerts');
$oAlert = new BxDolAlerts($this->_oConfig->getMainPrefix(), 'change', $iFileId, $this->_iProfileId, $aInfo);
$oAlert->alert();