This could be a handy update, both from a general user and an SEO perspective.
Today, Google has added a new element to its 'About This Result' panels in search results, which will provide more context about each result that you're seeing, including a brief overview as to why it's being shown in response to your query.

As you can see in this example, now, when you tap on the three dots menu next to most search results, you'll be able to access a new summary page which provides more detail on why you're being shown that web page, in response to your entered search terms.
As explained by Google:
"Starting today, About This Result will show searchers information about some of the most important factors used by Google Search to connect results to their queries. Because just as these factors help Google decide if a result may be relevant, they may also help people decide what result is useful for them."
The included notes are not in-depth, so their SEO research value is likely not major, but they do cover some of the major reasons as to how Google ranks its results pages.

Among the key elements displayed, the listings will show:
- Matching keywords - A simple, but important, factor Google uses to determine if information is relevant is when a webpage contains the same keywords as your search.
- Related terms - Google also looks for terms that our systems determined are related to the words in your query. If you search “how to cook fish in the oven,” we’ll also look for pages that have related terms like “bake” and “recipe.”
- Looking at links - When other pages link to a page using similar words as your query, that page might be relevant to your search. It can also be a helpful indicator of whether online content creators tend to regard the page as useful for that topic.
- Local relevance - Our systems also look at factors like the language you’re using to search as well as your country and location, to deliver content relevant for your area. For example, if you search "what day is trash pickup?,” it’s helpful to get results that are applicable to your city or state.
So again, it's more of a general overview than an in-depth SEO explainer. But even so, it may help provide some additional insight into how Google is ranking its response listings, with notes on relevant backlinks and how Google assesses things like local relevance.
In addition to this, Google says that the new results listing will also include tips on how to refine your results, and improve your responses in-stream.
"About This Result will show you tips for how you can get to what you really wanted. For example, you can put quotes around a word or phrase to get results that mention those words exactly, or use a minus sign to exclude certain words from your search."
It's not a major functional update, but it is worth noting from an SEO perspective, and it could help more people get a better understanding of how to make best use of Google to find what they're after.
The new 'About This Result' update is rolling out in English in the US from today, before being expanded to more regions in the coming months.