The same group that has been circulating that cancer post on Facebook also has a post on detecting strokes that has been showing up on my feed a lot lately. Any thoughts?

These are valid ways to recognize early signs of a stroke. The picture is very simplified, and depicts a clot obstructing the entire internal carotid artery (which is rare), but nothing I wouldn't expect to see on TV. In my opinion, this is a simplified post designed to convey simple facts to a broad audience in the hope of saving lives, and there's no reason to believe that it can't. For strokes, time is brain.

Edit: saw the cancer post, it needs references.

This stroke advice is fairly good. The point behind all the activities is to determine whether one side of the brain is not receiving oxygen due to a clot blocking a vessel. This causes that side of the brain to fail to send signals to muscles which causes an asymmetry in otherwise symmetrical motions (smiling, lifting both arms).

*edit: 'advise' -> 'advice'