Like most people this is one of my favourite paintings to stare at for hours. It is a painting by Osman Hamdi Bey which was originally called in Turkish “Kaplumbağalar ve Adam” (The tortoises and The man) but later with popularity it was generally named The Tortoise Trainer.
The painter painted two versions of this, one in 1906 and the other in 1907. The one documented in the photo is the first version and is located in one of the best contemporary/orientalist/classical museums of İstanbul Pera Museum (check the Pera Museum article). It is displayed in this Museum for the public and photos can be taken (without flash obviously).
It’s an oil on canvas with 221,5 x 120 cm dimensions. If you are an art lover I would definitely suggest you to have a stop at the Pera Museum just to only see this painting as its extremely worthwhile.