These are bared-teeth displays in human, rhesus macaque and Taíno material culture (shell face) from El Cabo, Dominican Republic. Alice V. M. Samson and Bridget M. Waller (human), Lisa Parr (rhesus macaque) and project Houses for the Living and the Dead (shell face). Figure courtesy of Current Anthropology.
Self-awareness can be difficult to prove, and thus far scientists have only been able to say with certainty that we humans possess the ability. Studies on other animals, however, such as bottlenose dolphins, magpies and elephants, indicate they are cognizant of their own thinking too.
My guess is that many other animals, including fish, are self-aware, but this latest study on macaques is particularly clever. It also looks to have been a not-too-unpleasant diversion for participants, as you can see in the video posted with this BBC News story.