Pinterest has begun rolling out a new Pin format, which includes some minor functional tweaks, and separates each Pin element more specifically.

As you can see in this example, provided by user @KenSchillinger, the update shifts the 'Save' and 'Send' buttons, as well as the options menu, to below the Pin image, as opposed to along the top bar in the current format. This will give the visual elements of your Pins increased focus, while the Pin image also will now also take up more of the screen, which is more aligned with vertical viewing.
When you scroll down (second image above) you can see that each section is now more specifically separated, with rounded edges defining each part. That, again, better highlights what you can do with each Pin, what you can learn about each, and then, what other Pins the platform thinks you might be interested in.
The new Pin format was actually spotted by reverse engineering expert Jane Manchun Wong, who tweeted about it back in April.
Pinterest is testing Board naming suggestions, redesigned Pin UI and "Set as wallpaper" for Pins pic.twitter.com/97HKCCH15U
— Jane Manchun Wong (@wongmjane) April 29, 2019
The change is also aligned with Pinterest's updated business profile format, which it announced last month. The new business profile layout will enable brands to use custom images, or even video, in their header section, and will include a new 'Shop' tab.

The rounded, separated elements will make it clearer as to what users can do in each section, which could help Pinterest encourage more user activity.
The new Pin format is in the process of being rolled out, with no definitive word on when it will be available to all at this stage.