OK, I’ll try again.
For example, using the default setup from ModX, I created a few chunks:
{{Art}}
<img src="assets/images/icons/pallet.png" border="0" title="Art" alt="Art"/>
and
{{Music}}
<img src="assets/images/icons/music.png" border="0" title="Music" alt="Music"/>
I then went to the tags section of the blog post and along with "demo howto miniblog" I added "{{Art}} {{Music}}", with the idea that any post related to Art, I could add the Art chunk and then see a graphical tag that if clicked on, would bring up any other posts with that same graphic tag {{Art}}
As you can see in the attachment, the icons show up fine, but when clicked, bring up all posts, not just the ones with the tag {{Art}} with the link being:
http://localhost/modx-0.9.6.3/index.php?id=2&tags={{Art}}&start=0
I hope this helps to explain it a bit better