Interesting how the screen reader will use the raster image for a PDF but not for the website. Based on the work I had to do to get the PDF to work, PDFs are a clusterfuck of glyphs floating in space and not really structured like HTML, so presumably they have to do the raster for the PDF so they can determine+optimize their own text flow but they're relying on the hierarchy of HTML to be enough of a guidepost that they don't need to OCR raster data. Thank you very much for replying!