Trompe-l'oeil is a technique used in art to create a realistic illusion of three-dimensional space on a two-dimensional surface. This technique is used to create the illusion of depth and perspective, and can be used to create a realistic representation of
From Wikipedia
Trompe-l'œil is an artistic technique that creates a highly realistic optical illusion of three-dimensional space and objects on a two-dimensional surface. Trompe-l'œil, which is most often associated with painting, tricks the viewer into perceiving painted objects or spaces as real. Forced perspective is a related illusion in architecture, and Op art a modern style mostly dealing with geometric patterns.