The new Instagram feature allows users to share carousels featuring photos of different sizes without altering their dimensions. During the editing process, a new resize icon appears, offering three options to resize photos, including an 'Original' option that keeps all photos in their original sizes. This enables users to mix and match portrait and horizontal photos in their carousels and publish them in their original dimensions.

To resize photos in Instagram carousels using the new feature, follow these steps:

1. Start editing your carousel: Begin by selecting the photos you want to include in your carousel.
2. Look for the new resize icon: During the editing process, you'll notice a new resize icon.
3. Click on the resize icon: Clicking on it will give you three options to resize your photos.
4. Select 'Original' option: One of these options is 'Original,' which keeps all your photos in their original sizes.

This allows you to mix and match photos of different sizes, such as portrait and horizontal, in your carousels and publish them in their original dimensions.

The new Instagram carousel feature is beneficial for photographers because it allows them to preserve the original composition and framing of their photos. Previously, photographers had to choose between portrait or horizontal photos or deal with awkward cropping when combining photos of different sizes. This update eliminates the need for third-party apps to arrange photos with white borders before uploading to Instagram, providing more creative freedom and enabling photographers to showcase their work in its original form.