Is there something to see outside the normal analog TV video frame?
In the analog days, there was often digital information transmitted in the top few lines of the picture. This could be quite visible on some channels and if you looked closely you could make out digital counters incrementing away.

Others used the blanking side bands for information which was not visible on the screen.

These methods were used to transmit information for various purposes including text based services Teletext, e.g  CEEFAX etc,. also  to pass along information to sub-broadcasters to allow them to insert local advertisements etc, as well as closed captioning.

However, most of this fell by the wayside with the advent of digital television where information has other methods to use that do not steal from the picture bandwidth.

Also, for NTSC analog color TV signals there is a colorburst signal that is transmitted at the start of each line. This signal synchronizes your TV to permit it to know which part of the signal that follows is intended for each color "gun". Again, this part of the signal is normally blanked out by your TV.

However, ultimately, it depends on the standard used in your locale and the station and carrier company.