Article preview is the first image that can be found in news article (must be inserted as an image, can be image from external URL). So since you haven't inserted any image into the article the first smiley which is an image was used.

So I have now added the same image that you have put into atachment directly from your website. But I'm not sure if it is the best image for this. So check it out and replace if if you feel necessary (you should be able to edit your own articles, if not do tel so that I forward this information to AthenaOfDelphi so that she changes the forum settings acordingly if necessary).

NOTE: When inserting image from URL you can chose to make a local copy of that image if it isn't to large (the image I now inserted is). Unfortunately I don't know what size limitation are set for this. You should ask AthenaOfDelphi for this.