Well, aside from you having uploaded the wrong image there is literally not much else that coulkd be at play here. So double-check and re-upload your watermarked image. Note that it may take a moment before it shows up due to the server's and your local browser's caching. In case of doubt refresh ther view a couple of times.
The image I posted here. is the same one that I uploaded to my site. I just wanted to show what the watermark looked like.
Seem all fine to me on the front page of your site.
I see it now. I can't understand why it took two days to pop up. But thank you all.