I'm surprised I haven't been able to find many published images showing photos arranged above a desk. A desk is a natural place to display family pictures or art to encourage or inspire while one talks on the phone or writes letters (if anyone writes letter anymore) or pays bills or reads the mail. Desks are expected to support a laptop at least, and often attract clutter that doesn't lend itself to studious contemplation or quiet listening--although a pleasant arrangement of photos can help.
Below, photos arranged over and around desks:
Above, nature photos including blue and gray series photos and white flowers in multi-matted and white-matted square black frames on a blue wall over a simple butcher block desk.
Cream-colored roll-top style desk with red-painted drawers, set off by additional free-standing cubbies, a red ledge, and black and white family photos in silver frames. The Polish pottery and German salt glaze stoneware add blue accents.
Adorable idea--hand drawn picture frames! From Apartment Therapy's Hakarl and Jili's house tour.