Cannot find uploaded image on server

I am uploading articles and images on a test website. The page looks fine, and if I look at the page source, I see: http://ift.tt/140hFO9

Now, if I log in with FTP and go to /public_html/wp-content/uploads/2014/12 I don't see header10.jpg - there are a number of other image files, but I can't see this one.

What's going on? Same is happening in other articles too. Any idea?