Basically, the artist may use the images I make for them in any way they please.  The sticky questions arise when someone else uses the images.

Scenario 1

If you have a show at a gallery and they use an image of your work to promote the show -- no problem -- this is well within the intended use of your images.  Essentially, it is your own self promotion through the gallery.

Scenario 2

If the same gallery were to use your image for their own promotion, such as in a brochure or web site, with no mention of you as the artist, then this is clearly a third party use and the copyright laws come into play.

The same is true for a publication that uses an artists image in their promotional material. These images are copyrighted and the artists and photographer should be credited and compensated.

Scenario 3

Say you are writing an article for a magazine for which you are being paid.
Even if the article is illustrated with images of your own work, the magazine should compensate the photographer for his contribution to the article. Just as the magazine is purchasing your article, it must also purchase the right to use the images from the photographer.