overlay.pic(vA);
overlay.pic does the same thing as draw.pic, except that the visual and priority screens are not cleared. This means that picture vA is drawn on top of the existing picture. Note that because fills only work on white surfaces, fills in picture vA which are not on a white part of the existing picture won't work. It's generally best not to use and fills in pictures that you intend to overlay.
Remember to use show.pic to update the screen once the picture has been overlayed.
Make sure the picture is loaded into memory before overlaying it.
draw.pic
load.pic
Drawing Pictures