When someone uploads an image and gives you credit as a collaborator, you will have the option to include it in your portfolio (the same as if you had uploaded it yourself). You might choose to display them all or select just your favorites. You will have complete access to all of the images in which you are credited. You have complete control over which images appear in your portfolio. You can turn images on or off at any time.
When you work with a lot of talented people you will enjoy a steady stream of new portfolio images to choose from, without having to upload anything.
TIP: if you and someone else upload the same image, you can credit each other without having duplicates appear in your portfolio. After you approve a collaboration, you will be able to turn it ON or OFF at any time and only one version of the image will appear in your portfolio.