Where destructuring in ES6 allows you to easily get properties out of an object, this shorthand property syntax allows you to easily push properties in.

let firstName = "Answer";
let lastName = "Question";

let person = {firstName, lastName}

console.log(person);  // { firstName: 'Answer', lastName: 'Question' }

let mascot = "Moose";

let team = {person, mascot};

console.log(team); // { person: { firstName: 'Answer', lastName: 'Question' },
                   //mascot: 'Moose' }