I am just coming to this, but DCVax-L is quite obscure, such photos do not drop into such high profile stories by accident. Newspapers and journalists do that when they know things that are not public and that they effectively cannot report. Granted, for posters to write a lot on the subject is speculative, but not without some reasonable degree of potential to be true.
There are not a bunch of partisan journalists looking for random opportunities to drop DCVax-L images into random "cancer" articles and that typically does not happen. It takes some thought and hunting and selection. And such photos are not necessarily available without licensing. So speculative, yes, without basis, not if they are sneaking in photos of DCVax-L in articles. A lot of times, journalists know more than they can say. Reasonable speculation, assuming such articles with such images exist. But speculation it is.