Logo not appearing on donation screen

[jallread]

Hello,

I cannot seem to get my logo to appear on my donation screen and cannot figure it out.  I have added the following to advance variables:

image_url=https://www.dropbox.com/s/file.jpg  (Paypal will not allow me to post the actual pic link.

I tried just linking the URL from our Facebook page, Dropbox and Google Drive.  The logo will not appear.  What am I doing wrong?  It is driving me crazy.  Here is the link to our donation page. 

 Any help would be greatly appreciated.  Thank you

Johnathon

Frustrated in Dallas

[smarty3]

This seems to be a common problem (we can't make it work at all either!).

So has anyone managed to successfully pass image_url in form/button? Or use it with a hosted button?

Are there certain circumstances where it appears or doesn't appear?