分享功能只有图片没有文字

https://rawgit.com/zhaomenghuan/mui-demo/master/example/share/index.html

 /**  
   * 分享发送消息  
   * @param {Object} share  
   * @param {Object} ex  
   */  
function shareMessage(share, scene) {  
       var msg = {  
             extra: {  
                    scene: scene  
             }  
       };  
       msg.href = "http://www.dcloud.io/hellomui/";  
       msg.title = "最接近原生APP体验的高性能前端框架";  
       msg.content = "我正在体验HelloMUI，果然很流畅，基本看不出和原生App的差距";  
       if (~share.id.indexOf('weibo')) {  
              msg.content += "；体验地址：http://www.dcloud.io/hellomui/";  
       }  
       msg.thumbs = ["_www/img/logo.png"];  
       share.send(msg, function() {  
              mui.toast("分享到\"" + share.description + "\"成功！ ");  
       }, function(e) {  
              mui.toast("分享到\"" + share.description + "\"失败: " + e.code + " - " + e.message);  
       });  
}