Nested Loops - lesson 6

I am doing lesson 6 on the introduction to Javascript, and I understand most of the code except for just one or two lines.

let bobsFollowers = ['James', 'Dean', 'Tony', 'Blair'];
let tinasFollowers = ['Luisa', 'James', 'Dean'];
let mutualFollowers = [];

for (let i = 0; i < bobsFollowers.length; i++) {
  for (let j = 0; j < tinasFollowers.length; j++) {
    if (bobsFollowers[i] === tinasFollowers[j]) {
      mutualFollowers.push(bobsFollowers[i]);
    }
  }
}

console.log(mutualFollowers);

I understand I’m pushing the result to the mutualfollowers array, but why do I need to include bobsFollowers[i] in the brackets?

    mutualFollowers.push(bobsFollowers[i]);

Thanks!

Because that is the value that matches the other one. The value is the argument to the Array.push() method.