Your selfie not quite what you wanted? Chose the wrong rating? No worries! While there currently isn't a way to edit the rating on the tracker. In this case, what you can do is delete it, then take a new one.
To delete a progress photo, from the MDacne App:
You can simply visit the "Tracker" section on the MDacne app, select the photo you want to delete and swipe left. That should show you a red, "delete" button to remove it.
From your Account Settings on the website:
Click Here to log in to your Account Settings
Select the photo you want to delete and click on the "x"