you can add bits of text or html using widgets in the sidebar, so technically you might be able to put an image link in the sidebar. i don’t know if you’ll be able to accomplish your desired affect though. i actually used to use the constructor theme for my wordpress website too. but then i noticed the sidebar images didn’t show up in IE (probably just something i did wrong). so i got fedup and just did my own layout in photoshop.
I updated to the newest version of constructor last week when prompted by WP. But, since then my banner image has disappeared. I haven’t changed anything else about the blog, and the image was there until a few days ago. I cannot figure it out!
I’m curious about the status of the Constructor theme. New versions of it do not appear as part of the regular WordPress upgrade process. Since the version I had no longer worked with the current version of WP, I went looking for it on the WP theme pages. I searched for it and found an entry for Constructor. However, when I clicked to it, there was no Constructor, only some suggestions for other themes.
I did find a more up-to-date version, but I’m left with the feeling that this theme is longer supported. Also, I can’t recommend the theme to less technical friends of mine if it takes extra steps to upgrade.