Instagram tests text overlays and image formatting within carousel posts

Instagram’s trying out some new elements for Carousel posts, with creators now able to add text overlays on individual images in a carousel, and re-format images in the display. First off, on text overlays. Some IG users are now able to add text to images within a carousel.
As you can see in this example, posted by Candidas and Nas Wander, the text option within the carousel composer now enables you to add captions that are overlaid on the carousel image. Which could open up a range of additional presentation options and considerations, especially for explainers, how-tos, etc.