Post is an imagine with 4 panels: Top title: before you leave the house check you have: panel 1: keys panel 2: wallet panel 3: phone panel 4: the vague sense that you've forgotten something
(I've never made text descriptions before, correct me for points)
Because some people can't see well enough to read the text on the image or identify what's happening in it. They use screen readers that read text out loud for them but those screen readers can't recognize the text or context of the picture either so we put a text description, so people with bad vision can still enjoy the memes through those screen readers