[Theme: Twenty Fourteen] Adding a static image to article/news page

I am having trouble adding and static image to my articles/news page. I have selected a static page as a home page and a static page for posts page. When I try to add the code for the image <img src=”#”/> on the posts page, on the beginning of archive.php, page.php, category.php, page.php etc (through Appearance –> Editor) I get to see the image on all of the pages that have a sidebar but it’s only missing on my posts page (that I selected as a static one). I have tried it on many other themes and I can’t seem to figure out how to add image or any other code to the page that displays posts, at the top before it generates posts. Can anyone help?

Thank you