Mahara allows you to provide feedback on other user's portfolios, blogs, or other activities listed under that user's views. For example, if you want to leave feedback on a blog:

1. Click on the title of the user's blog to be taken to the blog page. 

blog page

2. Once your are taken to the blog, click place feedback on the bottom left of the page.

place feedback option

3. Type your feedback into the box. You also have the option of adding an attachment, formatting the text, and choosing whether or not your feedback is viewable to the public. Once you have finished typing your feedback, make sure to click "place feedback". 

place feedback box