Data URIs don't show up in filmstrip

Anyone else have this problem? Recently, we changed some of our icons from inline svgs to now be handled by an external css with attribute “img{content: url(data URI)}”. These icons no longer show up in the filmstrip. Interestingly, a data URI handled with attribute “div{background: url(data URI)}” shows up fine. Chrome v102 was used for the tests which has full support.