It's shown as single rect with background and image on it.
According to SetWindowRgn on msdn:
method void CTaskbarNotifier::OnTimer(UINT_PTR nIDEvent) has two calls of SetWindowPos.
here code before for each call SetWindowPos
HRGN hRgn = CreateRectRgn(0,0,0,0); GetWindowRgn(hRgn); SetWindowPos(...); VERIFY( SetWindowRgn(hRgn, TRUE) != 0 );
coping rgn done because of windows dose not applies same region twice on window.