Earlier this year, Google and Twitter teamed up to embed tweets in your search results, and for both companies, the partnership made a lot of sense. From an end-user perspective, seeing popular tweets of ongoing events in your search results might give you the kind of answer you need right away. For popular Twitter users, it could even result in an increase of followers.
Up to this point, the search feature has only been available for mobile users, whereas in an new update, it's been spread to the desktop. Unfortunately, I can't currently see the feature in order to share a screenshot, but it's likely to look quite similar to the mobile implementation:
As with most new features that Google rolls out, it seems likely that this one will take a little while to affect users the world over. As mentioned above, I can't personally see the updated search yet, even when searching for hot topics (such as Ashley Madison), which could simply be due to the fact that I'm in Canada. Google's blog post was updated only yesterday, so it could take upwards of a week before most users will see it.