Chrome's new tab page is always undergoing design changes and improvements. One day you see shortcuts to downloads and bookmarks there, the next they're gone. The latest change involves article recommendations, which are now showing up for many users as larger thumbnails with text snippets.
The change appears to have been enabled server-side, but you can manually trigger it by going to chrome://flags and looking for the #interest-feed-content-suggestions. The flag seems to be responsible of using your Google Discover interests to come up with articles for you to read.
You might have already noticed that topics or sources you blocked in Discover used to still show up in Chrome — the latter didn't learn from the preferences you introduced in the former. With this new flag, Chrome seems to be pulling more from Google's Discover and following your preferences more carefully.
Left: New articles layout with mix of large and small cards. Right: Flag.
If the flag is enabled (regardless of any variation), the article cards in Chrome start looking more like Google Discover: a mix of large and small cards, with wide images for stories that are deemed important, and text snippets from the beginning of the article.
To go back to your regular article recommendations, disable the flag and restart Chrome. This will bring back the small cards with no text snippets.
Left: Flag enabled. Right: Flag disabled.
The flag and feature are available on all Chrome releases, from Stable to Canary, and there's no specific version needed in order to get them.