Hi,

I have tried to reproduce your problem, but both approaches you mentioned worked successfully on my solution.
For Runtime execution, you would not need any other implementation rather than the Image control definition in the Shell or UserControl View. If you would like to see the image in DesignTime instead, you would need to additionally reference the external assembly on the specific project.

Anyway, regarding your problem I would suggest you to verify the external assembly location:

• Assembly file should be placed on the Debug or Release folder where the solution builds and runs.
• The path of the image inside the assembly would be relative to the root assembly. So if you have the Image folder placed on the root of the project assembly, the source path would be as you correctly described.
  

if this did not help you, it would be helpful if you could explain what in particular would not work.

Regards.
Gabriel Ostrowsky
https://blogs.southworks.net/gostrowsky