From the audit picture question, select the edit button.
Alternatively, if you're audit has multiple question types, you could also choose the button on the left. Choose manage pictures.
Press on the edit button to manage picture attachments for the question. From there you can remove existing pictures if you'd like to.
Removing Picture Attachments from a Question
Select the image that you would like to remove. You should now see the delete button. Select the image that you would like to remove, then choose the delete button.