When I set a featured image, it is allways on the upper left corner of the post. Sometimes, like in this example post (http://martin-thoma.com/compare-planet-sizes/), I only have very few text and one image. But this image should not be on the upper left corner of the post.
Is there any way how I can this little post thumbnail image in the tag-overview (http://martin-thoma.com/tag/learning/) / category-overview without having it in my post? Could I tell wordpress that the image in the middle of the post is the featured image?