An integrated goggle clip is a built-in retainer on the back of the helmet that holds your goggle strap in place. Instead of just stretching the strap around the helmet and hoping it stays put, the clip locks it down securely so your goggles won't slip off—even during a fall or a bumpy run.
This feature is especially handy if you frequently take your goggles on and off throughout the day. The clip makes it easy to snap the strap into place with gloves on, which is a real plus on cold days when you don't want to fumble with bare hands. Most modern ski helmets include one for good reason: it's the most secure and convenient attachment option available.
If you ride hard, ski trees, or just want one less thing to worry about, an integrated clip is worth having. It's a small detail that makes a noticeable difference in convenience and security on the mountain.