We could visualize Bayes' rule as a pair of spotlights with different starting intensities, that go through lenses that amplify or reduce each incoming unit of light by a fixed multiplier\. In the Diseasitis case, if we fix the right\-side blue beam as having a starting intensity of 1 and a multiplying lens of 1, the result visualizes the calculation 0\.25 \* 3 = 0\.75:

Is this sentence supposed to have a part saying, "and if we set the left-side red beam… starting intensity of .25 and a multiplying lens of 3…" ?