Having has a few articles published myself (no, really!) it is different and over time, you actually start to think in your mind (I do anyway) the methodical steps to accomplish it, including what photos you would like to have and what you need to have, in the artcile to get the method across successfully.
I remeber when I had to do the whole think in film vs digital. The photos that you take are easy to do with a decent digital camera that you can accurately manually focus. Auto focus will drive you crazy.
The photo requirements referred to are way different from here as you are only working with the web, not 300 DPI printing requirements (or screens, or whatever). So there isn't really an association with what would go on the gallery pages vs into the journal, other than you could take the pictures shot of quality needed for the journal and resize them to put them on the gallery pages.