extra info on picture selection

inc/spot.php

@@ -278,6 +278,13 @@ class Spot extends Main
 		return $asAllFeedMessages;
 	}
 	
+	/**
+	 * Get valid pictures based on $sTimeRefField: 
+	 * - taken_on: Date/time on which the picture was taken (local time)
+	 * - added_on: Date/time on which the picture was uploaded (site's time: Settings::TIMEZONE)
+	 * @param String $sTimeRefField Field to calculate relative times
+	 * @return Array Pictures info
+	 */
 	private function getPictures($sTimeRefField)
 	{
 		$asPics = $this->oPicture->getPicsInfo();