The main objective of this paper is to provide an explanation on a conceptual level of how the Mirascope and the occurring image formation work. The physics behind a Mirascope--a well-known device consisting of two concave mirrors--is very complex. In literature, only either high level or very simplified and deficient explanations can be found. These explanations often lack a basic but detailed description on a conceptual level of the phenomena observable with the human eye. Therefore, this paper aims to give a physical explanation on a conceptual level to support learning processes in optics. Phenomena such as the diverse direction of the projected real image and the formation of the virtual image are clarified. As the focus lies on providing a basis to foster a conceptual understanding, there is no claim for a full and detailed explanation on the level of an exact ray analysis. In addition to a clarification of the content on a conceptual and educational level, suggestions for further investigations of the Mirascope with everyday items are given. The Mirascope is seen as an appropriate device for creating a learning environment following an inquiry-based approach in physics (teacher) education. This paper focuses on describing and explaining aspects of the Mirascope on a conceptual level.