The screenshot is one of three pictures included in a TEK feature in the latest issue of Acorn User magazine. The AU article is stretched out to three pages and includes a few snippets of new info along with the screenshots (one of which appears in the article twice). You can pick up a copy of the magazine for £4.20 from your local large Smiths, or you can order it directly from Tau Press.
Look out for our updated TEK preview which will hopefully include lots of new information about the long awaited real-time strategy game. If there's anything specific you'd like to know, post the question to this thread in our forums and we'll put it to Artex.