The effect is that something is placed inside a bag... The with a wave of a want you can make it disappear or even make it change!
since you brought it up and have asked about other things, some magicians have been known to load a large item into a change bag for a finale directly from a topit, ie for a cascade of sweets
also with two change bags you can throw a ball from bag to bag across the stage, ie put it in bag and make a flicking motion with your bag wile assistant catches said ball in there bag, finaly ending with each producing a large silk with little balls painted on them or
not here silks.
change bags can be used for stage mentalism tricks and others, iv'e been able to get away with using 3, count them 3 diferent change bags in the same show doing diferent effects without anyone getting clued in.
there are also some specialist change bags that include, pupets, insides that chage colour multiple times and mini ones for coin work /close up work.
hope this helps.