I love it! It's called the Camera Case Wristlet, pattern by Keyka Lou. The pattern is available for purchase and immediate download here: keykaloupatterns.com.
It took me a few hours from start to finish, but some of that time was spent studying the instructions and following them exactly (which is somewhat unusual for me). The pattern itself is very well drafted and instructions well-written. The bag measures 4.75 inches wide, by 4 inches tall and 1/5 inches deep. My favorite part is the very clever wristlet string.
The only modification for me was that I quilted the lining fabric in a diamond grid; I thought it would provide a little more support, but I'm thinking it was entirely unnecessary. However, it does add some interest to the lining, which I like very much. The best part is that the pattern calls for 1/4 yard (9 inches) of fabric each for the main fabric and lining, but can get away with a piece of scrap fabric measuring at minimum 12 inches wide by 8 inches tall. Of course, if you want to fussy cut any of the pieces, you will need more than the 12x8 piece.
The fabric is some left over scraps, which I used to make an apron way back when. The outer fabric is Anna Griffin for Windham fabrics called Maime. I tried to fussy cut the fabric so the motif was centered -- I think I mostly succeeded. You might not be able to tell from the picture, but there is a little pocket in the back, which is a neat little detail.
The brown polka dot lining is a Japanese fabric called Sevenberries. The lining fabric is especially scrumptious. It's smoother and lighter than the average quilting fabric. You can't see from the picture, but the polka dots are so rich in hue that they bleed completely through the back.