1. A method of joint generation of a mosaic of scenes, comprising: managing a multi-user mosaic joint generation session participated by a plurality of users by updating a graphical user interface (GUI) in a plurality of client terminals; receiving from each of said plurality of users a character selection made using a respective said GUI, said character selection is indicative of one of a plurality of characters which are imaged in a plurality of media content items, said plurality of media content items is mapped in a scene relation dataset mapping a plurality of possible connections between a plurality of pairs of said plurality of media content items, each of said plurality of possible connections is weighted; sequentially managing a plurality of iterations of user interactions held alternately among said plurality of users such that during each said user interaction iteration one of a plurality of expression indications is selected using a respective said GUI and one of said plurality of media content items is selected according to a relatedness to at least one previously selected one of said plurality of media content items, said relatedness determined using said scene relation dataset mapping, to represent said selected expression indication, said selected media content item images a scene with a respective selected character from said plurality of characters; and automatically generating a scene mosaic by stitching said selected media content items of said plurality of media content items into a sequence sequentially presenting a plurality of scenes imaged in said selected media content items.