const Observer = new IntersectionObserver((entries, imgObserver) => {
entries.forEach((e, i) => e.isIntersecting && onVisible(e.target, i) )
},{ threshold: 0.5 });
document.querySelectorAll('.IseeYou').forEach(e => Observer.observe(e) ); //
const onVisible = (elm, i) => {
TweenMax.to(elm, 3, { opacity: 1, delay: i*0.2})
};