unitsize(1cm);
real marge=3mm;
pair z0=(0,0);
pair z1=(0,2);

object objet_0=draw("LARGE ELLIPSE",ellipse,z0,marge);
object objet_1=draw("petite boite",box,z1,marge);

add(new void(picture pic, transform t) {
    draw(pic,point(objet_0,E,t){E}..{W}point(objet_1,E,t),Arrow);
});