I'm not sure what this product is supposed to do, but I like it. It is definitely not a primer in the sense that it doesn't make your makeup last longer, nor does it camouflage pores. It isn't exactly a moisturizer, but for me I guess that is the closest thing I can describe it as. In my mind, this is Chanel's version of Strobe cream by mac.
The product is quite a thick cream and sits a bit heavily on the skin, and yes, it gives a nice amount of shine. A gleam, not shimmer. Somewhat similar to how some sunscreens look: slightly oily and leaves a slight white cast. All of these things sound terrible, but I really like the product. The smell is lovely, and maybe it is a placebo effect, but it feels luxurious going on. I do try to leave it on for at least 5 to 10 minutes before putting on my foundation.
I can't pinpoint exactly what it does if anything at all, but I would definitely repurchase even though it is expensive because it lasts a long time since you shouldn't use much, the experience of applying is wonderful (especially on the neck!) and I think it has a slight psychological effect on me the rest of the day because I feel enveloped in luxury which helps me set a lavish mood.