@Vladis13 This appears to be correct, although it's not at all intuitive. The credits list includes everyone who's edited any page or any image in an export. Dmitrismirnov uploaded Yat-round-icon1.jpg which is why he's listed there. Also, bots are excluded from the list, which is why your bot user is not listed.

We could add a clarification to the list, but I'm not sure if it's widely wanted. What do you think? There was actually some talk a while ago about getting rid of the credits list, and only having a link to it (hosted by the ws-export tool), because that'd make the export process slightly faster and simpler.

Here's part of the task of removing credits: T276672: WS Export: Create separate credits page that can be viewed by everyone

@Samwilson About listing participants. Personally, I do not look at such lists in e-book files at all, and skip the title pages when I read them.
Moreover, usually the users who performed OCR, importing and proofreading indicate themselves under meaningless pseudonyms. In this case, a link to the wikipage with its edit history is sufficient.

Personally, I don't care if I'm listed as the editor of some wikipage. On the contrary, I would like to remove myself from the edit history of some pages, especially those of controversial fame. And I'm careful to keep my anonymity. I've been editing the Wikimedia sites for about 12-14 years.

However, there may be people who might consider it important to have their alias like "RuleZZZWikiEditor123JhonSmith" in the credits.