A PDF viewer evidently does exist for at least some browsers (Chrome, Edge, maybe others), although it currently suffers from some kind of rendering bug.
@bw-admin My question for the Bitwarden team is, how is this done securely? I imaging it starts by downloading the encrypted blob into the browser’s temporary file cache, but what next? Are any decrypted versions of the file stored on the device harddrive in the process of displaying the PDF? Does this rely on Acrobat software, and if so, could Adobe theoretically have access to the decrypted PDF file contents?