After you select your document, you will see your collaborators (those who you have granted sharing privileges in Google).
After you have selected who you will be communicating with, you will be asked how you want to share your feedback:
You will then start adding comments to your document. You have three choices- voice comments (seen below)-
You can also share via typed comments, or add links to resources! (See screenshots)
As you can see, this tool has great potential for authentic, meaningful feedback. This could be providing feedback to students, or even collaborating with colleagues on projects. They can even use Kaizena to respond back to you.