I don't know what the 3hearts image is, but the area it is in is output by templates/default/post_side.tpl
Looking at the snippet of HTML that outputs the image, I see:
<img src="3hearts.gif" hei="" width="42">
It is calling the image as though it were in the current directory when it needs to call it from the folder where it resides. This is why it is not working. Also, you might want to finish typing the 'height' attribute.
You may wish to edit this part of the template file to read something like:
<img src="{$config.BASE_URL}/images/3hearts.gif" height="42" width="42" />
Of course, change the path to wherever the image is if not in the image directory.