The Pixel 2/2 XL has a thick coating of primer and then another thick coating of paint over it which makes it feel like plastic. LG used this technique on the LG G5 and were criticised for it. It's not like other metal phones which anodise the metal to give it colour.
For example, the Pixel (2016 model) used anodised aluminium to colour the device. So what you felt was actual metal:
https://youtu.be/18nJ3hjUCTw?t=122
There is no primer or paint coating over the original Pixel (nor is there on many other metal phones). What your hand touched was metal and it felt great.
The Pixel 2 however used a thick coat of primer over the metal and then a thick coat of paint over the primer, which makes the phone look and feel like plastic:
https://youtu.be/BVKnt7H4zVc?t=124
With the Pixel 2/2 XL You are definitely not touching metal. That's a gripe I have with the Pixel 2 - they hide a metal body with a plastic feeling coating. This coating resembles plastic, scratches like plastic, discolours like plastic and will chip like plastic. Would have rather they went with anodised aluminium again, like on the original Pixel phones, or go with glass - either of them are much more favourable than going with the plastic feeling coating like they did with the Pixel 2 imo, so I'm glad they're going with glass for the Pixel 3.