From the Model Mayhem FAQ:

How do I unhide my images after resubscribing?
In case you were wondering, your images were not removed when you downgraded, they were just hidden. (Please also see the FAQ titled “Why were my images hidden when I downgraded?”) This makes activating your images and all your comments and views again really simple!

If your account is currently upgraded, first you will need to check the status of your albums. If they are hidden, the images inside those albums will also be hidden. You can quickly unhide your albums by accessing the album settings. This is what that looks like:

Then, if any of your images are still hidden, you will need to unhide them. This should be easy!

  1. Using the List view, find the check box next to "Select All" and click it.
  2. A new set of options should come up just to the left of the check box. The "eye" icon is your hide/unhide button. Here's a screenshot:

  3. You should now be able to successfully unhide all of your images at once with the simple click of that button.
  4. You can check the status of the image by looking at the buttons next to the image - if the image is hidden there should be a button that says "Unhide" but if it is unhidden, the button will say "Hide."

Your images should now appear in your portfolio. Please note that if you are a Premium member, only 1 album can utilize any privacy option. The rest must be public.