Click on the chart and use the left and right arrow keys to walk the categories. A dot plot is read exactly as a bar chart is — one category, one magnitude — so what the trace type buys is an announcement that names the chart the author actually drew. Press B for braille, T for text descriptions, and S to toggle sonification.
Read as a scatter, this chart would have had every one of its category labels coerced to a number: an x axis of a single repeated value, with the categories gone.