This photo, which allegedly shows two of the men who attacked Westgate shopping mall in Nairobi, is being circulated online by jihadist networks. It is the first photo to allegedly show a clear view of the attackers. Somalia-based militan group Al Shabab, which is linked to al Qaeda, has taken responsibility for the attack. 
The floor tiles in this image clearly match those of Westgate shopping mall, captured in photos by numerous photographers, including this one from the Times of London:
The photo was first spotted Monday on Twitter accounts purporting to be run by al Shabab militants (who call themselves “media soldiers”), which have popped up, been shut down, and reopened under new names numerous times since the start of the siege. This makes it impossible to track the first instance in which the image was posted.
The photo has been accompanied by the description “A gift to Muslims: a rare photo of our heroes during the operation.” It has also been relayed by well-known supporters of international jihad, such as Twitter user @al_khansaa2.
Given the angle of the shot, it looks likely to have been taken by a security camera. It could also be a photo or a screen grab of an image displayed on one of the mall’s security camera monitors. On Tuesday morning, the latest Twitter account claiming to represent al Shabab posted a version of the photo surrounded by the interface of LILIN, a popular CCTV software provider.