I look at a lot of Shopify themes as part of the initial review I do for every new JSON-LD for SEO Plus+ customer.
While reviewing one store, I happened to take a look at what their theme was adding for the structured data when I spotted this beauty:
This review field was added on a product with two customer reviews.
But that's not what that review field is for.
It's for Critic Reviews, i.e. a person writing an opinion piece on a product sold from a third party.
Not a store listing what their customers rated the product.
And I've already seen and reported on the damage of misusing that review field.
In this case, this popular theme is causing this damage by default.
I don't know how long this theme has been doing this, but there's going to be a ton of upset Shopify stores once Google removes their hard-earned Product Review Rich Results and replaces them with Critic Review Rich Results.
Additionally, and I don't know for sure yet, but notice that the author name is the company name.
Google's already started to fight self-serving reviews so these stores might not even get the incorrect Critic Review Rich Results, they might lose all of their Rich Results wherever they use that.
This is why it's important to use the correct structured data from JSON-LD for SEO.
I've seen well-intended but misinformed theme developers making mistakes in their code for years, but until now it's only been minor things that would cause Google to ignore their code (e.g. the infamous price with currency bug that's 3+ years old).
Using the review data inappropriately like this theme does is a fast way to get an angry Google looking very closely at your store and slapping a manual action on it.
(And I checked the official demo for that theme to make sure this wasn't a one-off change by the store, the official demo install has the exact same misuse of the review field).
Eric Davis