Config default image
The config_default_image module allows you to set a default image for fields that can be deployed with configuration. It stores the image's file path in configuration, rather than a content ID, ensuring your default images work correctly when deploying configuration between environments.
Image field formatter allowing to set a default image deployable through config management. It stores a file path into config, instead of a content uuid.
This addresses the problem that the core default image feature uses a file content. If you use config management (drush cex/cim...) you will deploy the config but not the content, so the default image wouldn't work in production.
A blog post about this problem: https://www.58bits.com/blog/2016/04/13/synchronizing-default-images-imag...