Recent research works suggest that human cognitive differences affect security and usability of picture passwords within a variety of interaction contexts, such as conventional desktops, smartphones, and extended reality. However, the interplay of human cognition towards users’ interaction behavior and security of picture passwords on smartwatch devices has not been investigated so far. In this paper, we report on such a research attempt that embraced a between-subjects in-lab user study (n = 50) in which users were classified according to their cognitive processing characteristics (i.e., Field Dependence-Independence cognitive differences), and further composed a picture password on a smartwatch device. Analysis of results reveal that already known effects of human cognition towards interaction behavior and security of picture passwords within conventional interaction contexts, do not necessarily replicate when these are deployed on smartwatch devices. Findings point towards the need to design for diversity and device-aware picture password schemes.