"A man who concentrates before a work of art is absorbed by it. He enters into this work of art the way legend tells me of the Chinese painter when he viewed his finished painting. In contrast, the distracted mass absorbs the work of art."
Walter Benjamin- The work of art in the age of mechanical reproduction.
A change, or super-slow movement, within the frame of a painting doesn't occur only in legends. Though the cause may be of a less romantic character, it is definitely possible that persons or objects disappear or reappear long after the artist has finished the painting. Through improper application of oil paint (a background which is too strong, lean on fat), over time places that have been painted over can reappear or painted figures placed in the background can disappear. Painted-over parts which have reappeared over time are well visible in Velázquez' horse with five legs or Pietro da Cortona's woman with three arms. These return in an almost ghost-like transparency. But where it really begins to become ghost-like is when figures literally start to look like ghosts. In many (church) interiors and other representations where the background was first painted carefully and the figures were added later, this is the case. Especially tile-floors are good at dissolving human figures (Hooch, Neefs).
(Dis)appearances | collection, 50 details from paintings (1400-1900), 10.2 x 15 cm. each
(Dis)appearances (detail: Velázquez)
(Dis)appearances (detail: Pietro da Cortona)