HI -- You know how you have the one rectangle as a caption shape--with the litle caption squiggle at the bottom of it-- like someone is speaking? See what it looks liek if you add the same type of squiggle to the other rectangle---- so both are BOTH a phone shape AND a caption shape (communication intersecting).
And maybe instead of the extra small intersecting elipses inside you have now, change that inner part to perhaps teh usual triangle "button" the others have been using---- OR something that in a simpoe line pattern forms an "M" using that "phone's left and right line borders as the left and rt sides of the M. IN fact -- I am looking at my typing letters rt here and theletter M has the downward arrow in it anyway. So you could try a couple versions. Color in the triangle/arrow maybe. Maybe it will look weird because the arrow is downward versus a usual "buttom arrow"--not sure.