A text slide post is a carousel: several slides within one post, read by swiping. The difference from a classic post lies in what's on the slides. Not a photo with a caption, but one statement per slide, set graphically so it works as an image in the feed.
ViralSpoon handles the design: your brand colors, your font, and your logo are stored and applied to every slide. You don't create a graphic, you provide a topic.
