Etsy sees it as a new item. You aren't "penalized" in any way, nor do you see a benefit. It's just a new listing.
As far as Google goes, Google made some adjustments to weed out sites that just copy from other sites in an attempt to gain standing in the search results. So you won't want to make your listings identical. That said, I think much of the advice about repetitive content is overblown. Make your descriptions true to your items, don't make your Etsy items/ descriptions identical to another site, and you'll be fine.