Trompe-l'il, which can also be spelled without the hyphen in English as trompe l'oeil, (French for 'trick the eye') is an art technique involving extremely realistic imagery in order to create the optical illusion that the depicted objects appear in three dimensions, instead of actually being a two-dimensional painting.These artists are able to depict an object so exactly as to make it appear real.
A style of painting that is intended to give a convincing illusion of reality.
The Conjurer is by Dutch painter Hieronymus Bosch or his workshop, executed around 1502.
Source: commons.wikimedia.org
Reference: Wikipedia The Conjurer (painting)
Picture by Dominique Antony This picture is very well painted and has many meanings with many possible answers.
Different people believe different things of what the painting actually means.
Source: commons.wikimedia.org
King Mahajanaka, having heard the wise words of the sage and returned to the palace, decides to renounce the wordly life. Here, he is announcing his decision in the palace, his mother standing behind him. Mahajanaka Jataka, cave 1, north wall. Ajanta, 6th or 7th century. (From "The Ajanta Caves", Thames and Hudson, 1998, reprint 2005, page 87)
Source: commons.wikimedia.org
Fresco of the investiture of Zimri Lim, 19th century BC, Royal palace of Mari
Source: en.wikipedia.org
Videos of Trompe L'Oeil Murals
Trompe L'Oeil Murals   
Eric Grohe murals/ Trompe l'oeil
Giacomo Sonaglia / Trompe l'oeil
trompe l'oeil 96-08   
Murals & Trompe l'oeil - Venetian Window