As reported by izendegi:

Once the workshop is closed, I can see the grade for submission and the grade for assessment, but there is no way to see the grades and feedback other participants gave to my submission. I click on "Grade for submission" and I can see my submission, but there is no way to see its grades or feedback, not even clicking the "Show more..." button. Using the browser they are shown below the submission as expected.

Looking at the test instructions in MOBILE-2238, it seems you have to change to submission phase (confusing!) which I tried doing, but still could not see the assessments or feedback.