Status updates on Facebook are a great way to keep people in the loop as to what is going on. You can inform your followers how many days they have left to submit an image, or if the contest is going to close early. If you plan on extending the contest due to the number of applicants and images that were received, you can also take to your Facebook feed to let your followers know about this. This will ensure you continue receiving images from them when hosting a photo contest.
No matter what you want your followers to know, what new hashtag you want to incorporate or what other changes you want to make to the contest, you can always use your Facebook feed to keep them in the loop. Not only are instant updates sent to email and to mobile devices, but more people are likely to see the changes and updates as they take place when they are linked to your social feeds on Facebook.