"One particularly annoying thing is that the graphics used in the blockbuster article – depicting the spy chip and its placement on the board – look to be purely illustrative"
The whole thing seems pretty weird. There are good reasons for keeping sources anonymous and not just dumping all the information and data handed to journalists into the public view, but usually it's made clear that said journalists have been shown stuff to make them believe something really is going on. Even if they don't publish it all, there are always comments along the lines of "We have been shown internal documents that appear to confirm...".
Except in this case, any hint of evidence seems to be missing entirely. One source claims to have heard something at a meeting, a second source claims to have seen a confidential report, and a third source claims to have seen some photos. At no point is it ever suggested that any of these reports or photos have actually seen by anyone at Bloomberg. Or anyone else for that matter. The graphics are purely illustrative because even the journalists at the heart of the claims literally don't have anything real to show us. At this point we should be debating exactly what parts of the internal report really mean, why bits have had to be redacted, whether maybe the whole thing is a fake, and so on. Instead all we can do is question whether a report even exists for us to debate.
The whole point of journalism is to say that something happened. We might not have all the facts and there might be plenty of arguments about exactly what happened, why, and what it all really means, but something definitely happened. In this case, all we have is that something might have happened but no-one has any evidence to say it actually did. When the entire claim is based on "someone said they saw a picture once", Bloomberg may as well be announcing that Chinese chips have been seen in a double-decker bus on the Moon.