What do you actually put on a pin when your niche isn't visual?

I write about small business bookkeeping. There is nothing to photograph. Every pin I make is a coloured rectangle with a headline on it and they all look like the same pin because they basically are.

Stock photos of laptops and coffee feel worse than the rectangles. Charts are illegible at feed size. What are people in non-visual niches doing that isn't just typography on a gradient?