When I configured in config.xml images which were in .jpg format

    <ProductImages>
        <Image>product-image-1.jpg</Image>
        <Image>product-image-2.jpg</Image>
        <Image>product-image-3.jpg</Image>
    </ProductImages>

They did not appeared during installation on the PerformInstallationPage as I expected them to. There was no error anywhere to be found (the binary creator has succeed without issues and the installer in verbose mode has not reported any error). It took several hours of guessing what could be the issue, until I changed their type to .png and it started working.

The documentation does not explicitly mentions allowed image types: https://doc.qt.io/qtinstallerframework/ifw-globalconfig.html (so I had no way to know it since Qt normally allows .jpg type)

I do not have problem that the QTIFW does not supports .jpg extension (if that is the intended behavior), but it would be nice if the issue appeared somewhere as a warning and was not silently ignored. The expectation is that when there is invalid input, you let user know.