Please check your browser Network debug tab (you can open it with F12), then refresh the page: the URL of the logo should be getting a 40x error. Can you check which one?
Oooh sorry, I overlooked that it is a custom app. The base64 blob is meant to be a placeholder since there is no logo for this app. Logos can be uploaded in the repository YunoHost-Apps/appsonly if the app is in the catalog.
Starting YunoHost 12.1 (currently in testing), you will be able to upload your own logo.
I thought it was no longer possible to use this method to install themes on the Yunohost Portal?
That we should now go through the Admin Yunohost domain interface.
When I go in:
cd /usr/share/ssowat/portal/assets/themes
-bash: cd: /usr/share/ssowat/portal/assets/themes: No such file or folder
cd /usr/share/ssowat/portal/assets/
-bash: cd: /usr/share/ssowat/portal/assets/: No such file or folder
cd /usr/share/ssowat/portal/
-bash: cd: /usr/share/ssowat/portal/: No such file or folder
This method is apparently no longer relevant.
My request is not about a background on the Yunohost Portal, but about favicon that can be seen on the tabs, as here on the Yunohost Forum.