方法中this指向？

Question

  class BtnComponent{

    constructor(){

      this.state = {isLiked: false};

    }

    //改变文本

    changeLikeText(){

      var likeText = this.el.querySelector('.like-text');

      this.state.isLiked = !this.state.isLiked;

      likeText.innerHTML = this.state.isLiked ? '取消' : '点赞';

    }

      stringDom(string){

      var div = document.createElement('div');

  

      div.innerHTML = string;

      return div;

      }

      render(){

        this.el = this.stringDom('<button class = "like-button"><span class = "like-text">点赞</span><span>AA</span></button>');

        this.el.addEventListener('click', this.changeLikeText.bind(this));

        return this.el;

      }

  }

这是一个点赞的插件，请问这句代码中后两个this分别指什么？为什么这么写？this.el.addEventListener('click', this.changeLikeText.bind(this))