You can add a comment to a section of text, an object or the entire drawing in Google Drawings.
- Highlight the item you’d like to comment on.
- Go to the Insert menu, and select Comment. You can also use the shortcut Ctrl+Alt+M(PC) or Cmd+Alt+M (Mac) to insert a comment.
- Click Comment to add it to the drawing for your collaborators to see.
- Type your comment in the box that appears to the right of the document, and press the Comment button
- To resolve a comment or discussion thread, click the comment and click Resolve.
To view the comment history on a thread, including resolved comments, click Comments in the upper right of your document.