Why do Leaders need a Positive Televisual Image?

-Neil Kinnock's at the Sheffield Rally may have put Doubt in Voter's Mind as he seemed to be out of touch -2010 Debate between the 3 Main Parties could be why Conservatives didn't get a Majority. Nick Clegg performed Strongly and the 'Cleggmania' gave Cameroon a Hung Parliment -2015 saw Ed Miliband fall off a Stage in front of a Live TV Audience which made him as a not Strong Leader [He seemed Cringe] -May didn't want to be in a Live TV debate led to her Leadership being attacked. Green Leader Caroline Lucas MP said that 'first rule of Leadership is that you turn up'