Speed of Light is much faster than speed of sound.Why my TV,when switched on,Sound comes first&Picture later?

c boss v have 2 consider 2 cases.one is "in d rx section of t.v sound detecting sys is d first section,video section is then".the 2nd case is "it takes a finite time to construct image on d picture tube plates.this will perfom by tracing the electron beam or after demodulation of video information the electron beam uses this information to lit up each pixel among lakhs of pixel on d raster"