Okay, let's try a less "silly" thing. Is altering a picture in an article or a book usually considered a part of normal editing?
Editing happens in all books, but that doesn't mean that all editing is honest or ethical.
Of course it's normal. Nowadays it's widespread. Pictures are altered more than words. Airbrushing etc. etc.
It's not down to the fact it's done, as I said it's done all the time and now even more so.
Political photos, t'v you name it. It's obvious. The why is so simple I fail to see how anyone could not be aware of it.
The image, the impression the person, the company, the group, whoever wants to project.
Anything that doesn't project that precise image is edited out.