Applications for Education.
Copying images from Google Docs to Google Slides or the reverse of that procedure can be handy to trainees who are producing presentations about reports that they have actually put together. For example, this could be handy to a trainee whose report consists of a chart or diagram that she or he plans to also talk about during a slideshow presentation.

When you submit an image and insert it into a Google Document, it must then also be available through Google Drive to insert into future files and into Google Slides. There is an easier option if you want to copy an image from a Google Document to another one or into Google Slides.

See this brief video to see how to copy images from Google Docs to Google Slides and back..