I have attached a screenshot of the section that I believe you are referring to. The reason that the students are not seeing these comments is because they have not been posted yet. If you post the grades this comment will appear on a transcript record and the student will be able to view it via My Info > Transcript ST in the student portal or once report card is published, this information does not appear in the Academics tab of the student portal.
When it comes to the post columns, Comments, G1T, G2T, FG, etc. these marks and comments only become available to the students once they have been posted to the transcript record.
In the student portal, the students should be able to see calculated marks, such as the averages as well as any Public assignments under the Academics tab. They can also see comments left on specific assignments but based on the screenshot you provided I believe your teacher was just trying to enter a term comment.
When you are looking in the School view Grades TT > Grade Input ST the columns with the "pin" icons change colours based of if they are posted, closed, or not posted. As you can see in my screenshot the column G3T and ComT3 the "pin" icon is green which means these columns have not yet been posted to the transcript record and the window to post is open. If this icon is red the columns have been posted to the transcript record and the window to post is open. If this icon is black the window to post these columns has passed and teacher's cannot post from their Gradebook.