I think that
SH1oN means by "smart stretch" a special subtitle option like many wide screen TVs offer for displaying 4:3 broadcasts with subtitles: these TV's have a feature to enlarge the picture somewhat unevenly (or somewhat distorted if you want), to the effect that the lower part of the screen (where usually subs are positioned) is treated different from the main part of the screen. Though this unevitably results in a somewhat distorted screen at the very bottom, it isn't really annoying and two lines of subs are shown without further fuss.
