Here are some things to consider when inserting a comment in PowerPoint:

1. Select the text or object that you want to comment on. You can comment on content in the slide, such as text, images, shapes, or tables.
2. Click the Review tab. This is located on the ribbon at the top of your PowerPoint presentation.
3. Click the New Comment button. Look for the icon with a text bubble. This is usually in the Comments group.
4. Type your comment. You can also format your comment using the tools in the ribbon.
5. Click the Save button. This button is usually located in the top-left corner of the screen.