That would be a fail of the fingerprinting protection. A properly set up TOR browser for example should not allow that detection by any means. If you know how to detect it, please report it as a critical vulnerability.
I could think of maybe some edge case behavior in webrenderer or js cavas etc., which would mainly expose info on the specific browser and underlying hardware, but that is all of course blocked of or fixed in hardened browsers.
Further, if you have a reliable method, you could sell it off to for example Netflix, who are trying to block higher resolutions for Linux browsers but are currently foiled by changing the useragent (if you have widevine set up).