According to: https://stackoverflow.com/questions/34328735/imageable-type-is-not-setting-for-polymorphic-associations and https://stackoverflow.com/questions/2494452/rails-polymorphic-association-with-multiple-associations-on-the-same-model
According to: https://stackoverflow.com/questions/34328735/imageable-type-is-not-setting-for-polymorphic-associations and https://stackoverflow.com/questions/2494452/rails-polymorphic-association-with-multiple-associations-on-the-same-model