Thanks for posting!
When you right-click on a container field and opt to insert a picture, the dialog that allows you to select a file should have a small checbox in the lower left hand corner that says "Store only a reference to the file". You may want to make sure that this option is not enabled when you select your image.
Global fields behave a little differently on hosted files. Specifically, the value of the global field is set by the host. A client can change it but the change will only last for that clients session and no other clients will see the change. The solution to this it to either have the global value set by a start up script or set it in a copy of FileMaker Pro locally and then upload it to the server. For more information on global fields, please see knowledge base answers #3604 and #5895:
The solution to this it to either have the global value set by a start up script or set it in a copy of FileMaker Pro locally and then upload it to the server.
I've discovered a third fix that I use whenever I upload a file to the server and then discover that I didn't first load the desired default value into a global field:
Write a script that assigns the correct value to the global fields. Create a schedule on the server to run this script, but leave it disabled so that it doesn't run automatically. When I need to set the globals, I use the server console to run the script. Since scheduled scripts run from a "host" perspective, the changes made to the global field are retained.