I was testing the iPhone X's image quality capabilities and it seems to do a nice job with small products using the second (X2) lens. It captures detail very well at short focusing distances and blurs the background optically (no software blurring or post-processing, unlike portrait modes).
Here are a few shots of bracelets (handmade in Mexico) on a reflective black surface and a white wall as a background:
The iPhone X performance was pretty consistent across more than 20 bracelet shots. It had good exposure and focus, however we can see noise reduction artifacts if we look closely at the out of focus areas. The light source was a big window on the other side of the room and there were no extra lights.