Visual Conceptual Modeling plays a critical role in advancing robotics by enhancing expressiveness and facilitating collaboration through intuitive visual representations. This paper presents an exploratory literature review of 47 relevant papers, systematically analyzing the application of visual modeling techniques in robotics. The papers are analyzed along seven key criteria to give a comprehensive assessment of their characteristics. Our study shows that despite the increasing adoption of visual modeling techniques, there are still significant gaps in the use of advanced visualization features such as 3D representations and orientation differentiation. The findings thus highlight the potential for enhanced expressiveness through the integration of 3D representations, which could bridge the gap between simulation models and conceptual models. Finally, we propose future directions for the development of more effective visual modeling solutions tailored to robotics.