He's a space news reporter at Ars Technica. It makes sense they'd be one of the first to get the SpaceX news release. It has too many characters to fit in a tweet, and even if it could fit, embedding an image of the text sets it apart from the tweeter's introduction and makes it more readable. It's standard practice on twitter to use images for blocks of text.

> Why would you confirm something with the screenshot of notepad "officially" when you have a twitter account?

I figured it was because they didn't want to be constrained by a character limit. It allows them to use very specific language.

To keep it out of search results. They can delete the image of the text whenever they'd like, and poof