I'm the author of the article and the editor of the section: a while back we decided to use illustrations rather than photography for this section of IEEE Spectrum—it was a style choice, but it gives us more options in terms of showing components and process diagrams.
When we made the switch, I was initially concerned about this as well, but as is often the case, well-chosen limits can promote creativity, just as say, choosing to work only in black and white might be done by a photographer or comic book artist, or choosing to use pixel art in a game built for modern systems. The illustrations also give a unified, and distinct, look to articles in the Hands On section, which is important in a crowded domain: the qualitative and quantitate feedback we've gotten since we made the switch has been quite convincing for me.
It's the nature of abstraction: just like a map versus a satellite photo, it allows us to more easily highlight particular features. It also allows for options like cutaways and x-ray style images, and allows us to compose scenes how we like without the hassle of setting up physical shots.