Switching method when reading an Addressable scene

in your scene your AddressableObject (which isn't really addressable) has a direct reference to the image. That means on load of the scene, that SD image will load. After the load is done you could change the linked image using Addressables.

take a look at https://github.com/Unity-Technologies/Addressables-Sample/tree/master/Advanced/Texture Variations for a example of what you're trying to do.