Here's the difference I see between this one and others, including my all-time love, Touche Éclat. It's meant to retouch your foundation in addition to serving as a highlighter. Not all of them do that.
Lancôme makes a relatively new foundation called Teint Miracle, 10 years on the making. It's said to recreate the true, natural light of perfect skin, with a lit-from-within look. I have always liked Lancôme's foundations (I used to wear one exclusively a long time ago). The Instant Retouch Pen for all skin types was created to do the same thing: add a lit-from-within look to the areas you want to touch up. It can be used as your foundation in a pinch.
This is the first Lancôme perfecting pen enriched with micro-fluorescent particles for a surge of true, natural light. The portable pen can be used anytime anywhere to retouch - illuminating, smoothing, and visibly eliminating imperfections. The fluid blends seamlessly and easily (very fluid texture), and it's instantly hydrating. Unfortunately, from my perspective, some of its hydrating properties come from propylene glycol (PG), the ubiquitous, inexpensive hydrator our beauty companies don't seem to be able to "lose." While it has some nice hydrating ingredients that score plus points in my book, the PG gets a minus from me. Too bad - otherwise, I really like Teint Miracle.
You may not care about the PG as much as I do. If you want to try a new click pen highlighter that will immediately brighten your skin, check out Teint Miracle at your Lancôme counter. It's available in multiple shades.
I purchased the lightest shade, #1. I took a photo of it indoors in full sun. At the top of my photo, I applied the product straight from the pen. Below, I blended it. Blended, it's my skin tone, so all you will see is a gleam in my photo - if that. I can assure you that the shine in the center of my arm is primarily from the highlighting effects.
You can purchase Teint Miracle at Lancôme counters. They told me they are having trouble keeping it in stock at Neiman Marcus.