Currently, I can't or I don't know how to differentiate between posts that were posted through desktop/ mobile web browser/ app.
Have you considered displaying a wise-stamp or any icon to let readers know that the post was published through mobile/tablet web browser?
I have tried posting a couple of answers in EL&U from my Android mobile browser and to be honest, I am finding it very difficult to add markdown formatting to my answers. More often than not my answers end up looking bland, less appealing to readers and disoriented due to lack of formatting. I know I can ace mobile web with more practice but I can never match the speed and accuracy of a standard physical keyboard and mouse.
This will allow readers of the post to excuse any formatting / alignment errors.
(Just a wild guess...) This could possibly allow more statistical analysis for users of mobile/phablets vs users of desktops/laptops.
This may be a trivial change request that might not add any UX benefits...
Please add if you find any in comments.
Has this been already discussed before(I don't seem to find matching posts)? If not, is this worth considering?