What steps will reproduce the problem?
(1) https://mounirlamouri.github.io/sandbox/media/dynamic-controls.html
(2) Set width to 200
(3) Observe that the volume slider is visible even though the mute/unmute icon is not.

Without the mute/unmute icon, this state is confusing because it's not obvious that the volume slider is in fact the the volume slider. It almost looks a continuation of the timeline slider.