When browsing a "canonical" domain sites often detect a mobile browser by the User Agent header and redirect to m.* (such as m.facebook.com).<p>It's a bad habit to have 2 versions instead of one fully responsive one, but this is a question for another debate which has seen lots of discussion already.<p>But somehow sites (and again, I include Facebook as a prominent example) don't sniff the other way around when a user comes to their m.* domain from a desktop browser and don't redirect them to the canonical domain.<p>That results in people browsing these sites from mobile, sharing m.* links which people then open in their desktops and see a very weird mobile-oriented display.<p>My question is why do they not do that detection? is it pure negligence or is there something else behind it?
I would guess that, in most cases, a mobile-specific site accessed on a desktop is still going to be far more usable than a desktop-specific site accessed by mobile.<p>Either way, as you mentioned, its a solution to a problem where the original solution itself wasn't great in the first place.
One argument I could see is that the canonical url is ambiguous where the m.* url is more likely to be intentional. If I am on my mobile phone, I will probably type facebook.com into the address bar, because switching keyboard context for the url would be more difficult. If I am on a desktop I am unlikely to type in m.facebook.com, unless that is the url that I really want.<p>If you think about it this way maybe it would make sense to have a d.* and m.* url. The URL without a suffix will remain the ambiguous case and you will be redirected based on which platform you are on. If you would prefer a specific version of the site, you could request it explicitly.<p>Maybe some type of prompt to easily switch versions if it recognizes a url/platform mismatch would be helpful in the case of shares that you described.
A few people might have intentionally used the mobile version because it loads faster for them or more readily presents the information they wanted. I'm not sure I can think of a site that I currently use that way, but I think I've seen people do it in the past.