I want to display an newsarticle in another context then the news container that the newsarticle is fysically in. How do i do that the best way? I rather not want to have the article in two containers... please help me with some examples, thank you.
In EPiServer terms, "mirroring" means transferring content between two different sites. I assume what you are really mean is cross-publishing within the same site, or displaying the same content in several places ("in another context") on your site.
Cross-publishing is usually done by creating a new article under Container X, then using the "fetch data from page" feature, linking to the original article under Container Y. There's also a Cross Publish plugin. However would lead to duplicate articles, which you don't seem to want.
You could check out Anders Hattestad's blog post where he achieves cross publishing without duplicates by faking the article's location.
If you just want to show/list your article in a news list or similar on another page on your site, you could