you need the link with an image tag at the end (.jpg/.gif/.etc)
on desktop you just right click the image and "copy image link", but it's a pain in the ass if you're doing it from your phone, you have to make it full screen and then share that link
post it with a lower-case L at the end, so if its "xxxx.jpg" make it "xxxxl.jpg", and then it will make the pic a more reasonable size and we wont have to see every hair on your nutsack in ultra-hd