Lesson 16 (Lesson 16 Part 1 Views Custom Field PHP)

Referring to your 16th lesson (Lesson 16 Part 1 Views custom field PHP) on Drupal, it is clear that this is done using the Views custom field. I need the link to add an image to be displayed only in one place, rather than under each image as shown in your lesson, for example, at the very top of the gallery. Thank you in advance