You need to upload that photo from your hard drive onto a web site, and then link to that. The link needs to start with http://..... All you have done is provide the file name on your own hard drive, which the rest of us can't link to.
Look at where other people have photos posted, and then try some of those sites. There are a lot of free photo web sites around, you should find something that works.
This is the post my husband built for me. I was originally going to buy one but he told me he could do that easy. I told him yeah right. (He is not one for these sorts of projects.) So the next weekend we went to Home Depot and later that evening I had my cat post! For half the cost no less. Its pretty basic, not as nice as yours, but Amber loves it. She climbs to the top, which is just above where the pic ends. You can probably tell its been well used!
How sweet! That would be great, but I'd have to sneak it past my husband. He insists I don't need to buy one & that he'll make a nice one for me (but I'm still waiting for him to start...sigh). I wouldn't want to hurt his feelings. I just need to give him a nudge about it again, I guess.