The CBRE Urban Photographer of the Year competition – now in its ninth year – encourages professional and amateur photographers to capture cities at work. Here: Dog Walker – 15:00. The competition allows photographers to enter up to 24 images, one representing each hour of the day. (Photo by Johanna Siegmann)

Born with a rare condition, the artist has chronicled her life in portraits – capturing everything from her tattooed prosthetics to the tentacled creature she stitched together on the shores of Naoshima. Here: Ophelia (2013). From a series of photos of imagined women exhibited at the 2013 Aichi Triennale. Here, Katayama invokes Hamlet’s tragic heroine, after the painting by British pre-Raphaelite John Everett Millais. (Photo by Mari Katayama/The Guardian)

These images capture the intricate details of minuscule snowflakes, moments before they melt. The shots were taken by Don Komarechka, 31, who has had a lifelong fascination with all things macro – especially snowflakes. The professional photographer says people often don’t believe that his pictures are real because they’re so perfect. (Photo by Don Komarechka/Caters News Agency)

Angele Blank, right, and Virginia Promeyrat wait for the start of the Greenwich Village Halloween Parade, Saturday October 31, 2015, in New York. (Photo by Tina Fineberg/AP Photo)

A boy holds the remains of a mortar shell which hit a residential building in the village of Staromikhailovka, outside the separatist-held city of Donetsk, Ukraine, May 24, 2016. (Photo by Alexander Ermochenko/Reuters)

Emily Ratajkowski, left, a cast member in “We Are Your Friends”, walks the red carpet at the premiere of the film at the TCL Chinese Theatre on Thursday, August 20, 2015, in Los Angeles. (Photo by Chris Pizzello/Invision/AP Photo)

A goose sits atop eggs in a flower bed on the Wisconsin Ave. bridge, Friday, April 19, 2013, feathers ruffled in the cold blowing wind and snowflakes. The goose is near to the statues dedicated to Gertie the duck who made international news when she built her nest next to the same bridge in 1945 and captured the attention of Milwaukee at the end of the war. A statue commemorating “Gertie the Duck” sits on the other side of the bridge. The goose has several eggs she is sitting on. (Photo by Mike De Sisti)

A stewardess holding a lightsabre poses for photos with visitors during a tour of the Star Wars themed All Nippon Airways ANA R2D2 Boeing 787 Dreamliner aircraft at Singapore's Changi Airport November 12, 2015. The aircraft was opened to the media on Thursday as it makes its first Asian stop outside Japan. (Photo by Edgar Su/Reuters)