So I must've made a mistake - ezxmlexport does export the <img> element but it's the data_import extension that parses this XML that's importing everything else, but is rippin gout the <img/> tag from between <a> tags.
If anyone knows a little about ezxmltext in general, how eZ handles it etc, I'd be interested to hear from you as I'm struggling a little going up as far as eZSimplifiedXMLInputParser and eZXMLInputParser.