added comment about how copies flow from index state
added comment about how copies flow from index state

gengjiawen/desktop,hjobrien/desktop,kactus-io/kactus,say25/desktop,say25/desktop,desktop/desktop,desktop/desktop,artivilla/desktop,say25/desktop,artivilla/desktop,BugTesterTest/desktops,j-f1/forked-desktop,j-f1/forked-desktop,hjobrien/desktop,shiftkey/desktop,artivilla/desktop,gengjiawen/desktop,BugTesterTest/desktops,hjobrien/desktop,artivilla/desktop,kactus-io/kactus,j-f1/forked-desktop,desktop/desktop,shiftkey/desktop,j-f1/forked-desktop,say25/desktop,shiftkey/desktop,shiftkey/desktop,hjobrien/desktop,gengjiawen/desktop,gengjiawen/desktop,BugTesterTest/desktops,desktop/desktop,kactus-io/kactus,BugTesterTest/desktops,kactus-io/kactus