Social media and crediting images

Non-commercial or commercial publications have the same requirements. Either you need to credit or you do not need to credit. You need always to credit, when you are using the asset in an editorial way, even if it is not an editorial use only picture. Where you credit is your choice, it just needs to be obvious what elemnt has been credited. For blog articles, I would credit under the picture, especially if you have more than one picture.

See screenshot.   Notice the CREDIT LINE.  That's the source of this Editorial Image.

If you are referring to an image licensed from the Adobe Stock database, there is no need to include an author credit, unless it is an Illustrative Editorial image, in which case the credit can be a small legend just below the image.