If work is removed from a portfolio, then the original file will still be in the assignment folder. Students can only remove work from their own portfolios if they themselves added the item.
Removing from the Portfolio on the iPad
To remove work, you can swipe left on the file while in the portfolio and then tap on the red X. You can also remove items from the assignment folder. Swipe left on the file and tap on the star icon instead to remove it.
Removing from the Portfolio on the Web
To remove work, navigate to the file and hover your mouse over it. Click the arrow that appears and then click Remove from portfolio: