I noticed that if you select to use Image Tracker code for Piwik the URL parameters are:
/piwik.php?idsite=1&rec=1
But for the fallback in the regular tracking code the parameters are:
/piwik.php?idsite=1
It is explained that rec is used to “force” the request to be recorded, presumably without it… nothing is tracked? Can someone clarify how it actually works and why rec isn’t present in the regular tracking code?