Image sharing on linkedIn and Twitter share button not working in meteor

help
1

Hi,
i am new in meteor, i am trying to use social sharing in meteor and it is working fine for facebook, email, g+, But I am unable to show the image for linkedIn and twitter.

here is the info of meta tag related to linkedIn and twitter

  <head>
 <!--linkedin-->

<meta prefix="og: http://ogp.me/ns#" property="og:type" content="object" />
<meta prefix="og: http://ogp.me/ns#" property="og:image" content="https://herokujobapp.herokuapp.com/images/JobApp_HappyBuddy_App_LinkedIn.jpg" />
<meta prefix="og: http://ogp.me/ns#" property="og:url" content="https://herokujobapp.herokuapp.com/" />

<!--Twitter -->
<meta name="twitter:card" content="summary_large_image">
<meta name='twitter:site' content='https://herokujobapp.herokuapp.com' />
<meta name="twitter:image" content="https://herokujobapp.herokuapp.com/images/JobApp_HappyBuddy_App_Small.png"/>

</head>

I am using " lukemadera:social-share" package for social sharing. Here is my code to use this package.

  MainPageopts: function() {
  var MainPageopts ={
    facebook: true,
    twitter: true,
    linkedIn: true,
    googlePlus:true,
    shareData: {
      url: 'https://herokujobapp.herokuapp.com/',
      subject: 'Are you looking for a new job? Try JobApp!',
      description: 'Are you looking for a new job? Try JobApp!',
      defaultShareText:'Are you looking for a new job? Try JobApp!',
      title:'Are you looking for a new job? Try JobApp!',
      desc:'Are you looking for a new job? Try JobApp!',
    },
  };  
  return MainPageopts;
}

Can anyone suggest possible reason for this and its solution.