\node [yshift=-23mm, xshift=-1cm,anchor=east] at (img1.north west) (Compositor) {White cursor in Compositor};
\node [yshift=-28mm, xshift=-1cm,anchor=east] at (img1.north west) (Timeline) {White cursor in Timeline};
\draw [->, line width=1mm] (Compositor) edge ([yshift=-23mm] img1.north west);
\node [yshift=-23mm, xshift=-1cm,anchor=east] at (img1.north west) (Compositor) {White cursor in Compositor};
\node [yshift=-28mm, xshift=-1cm,anchor=east] at (img1.north west) (Timeline) {White cursor in Timeline};
\draw [->, line width=1mm] (Compositor) edge ([yshift=-23mm] img1.north west);