It was showing yesterday but only on last page, after modifying template and replacing placeholders with sections and embedhtml i get this issue.
Checked images - mime type is png. Path to image is also correct one.
you can see document here : http://simco-ion.nl/typo3conf/ext/uwkm_offer/Classes/Controller/document.docx
and for template it's: http://simco-ion.nl/typo3conf/ext/uwkm_offer/Resources/Public/Templates/Quotation_front_nl.docx
path to image : http://simco-ion.nl/typo3conf/ext/uwkm_offer/Resources/Public/Images/simco_footer.png
so not really sure what could be else go wrong here.