When a client reviews your work and finds it unsatisfactory, they will reopen the gig to you. This puts it back into your to-do list, and it also sends you an auto-generated email telling you that the client has asked you to update your work.
A client may ask you to update for several reasons (they will generally provide you with an explanation when they reopen the Gig, so be sure to check your in-app messages). If they did not provide an explanation for the update request, then follow these steps:
Re-read through the instructions to be sure that you didn't miss anything.
Re-read through the questions and answers to be sure you didn't leave any questions blank or leave any conflicting answers.
Double check that your photo tasks have photos, have captions if necessary (add captions by tapping on the uploaded photo), and that all photos are uploaded into the correct task number. Also, be sure the photos don't have any of these problems: blurry or overexposed, taken at an incorrect angle/distance, text is not readable or is cut-off.
If you cannot figure out what is wrong and the client did not send you a message indicating what portion of your Gig was incomplete, we would recommend sending them a message directly through the Gig details page on the app asking for clarification. After a gig is reopened to you, you generally have 24 hours to tap the "submit your work" button again before your new deadline expires - so if you don't hear from them promptly and you feel confident that you completed the gig properly, you can submit the gig again.