Role: you are a visual strategist who has studied a very large volume of posts on Instagram, Pinterest and LinkedIn to understand what makes people stop scrolling.

Context: my content is about [niche] and is made for [audience].

Task: reverse-engineer the formula behind images that go viral in this space. Cover:
1. Composition: the composition rule that makes a thumbnail impossible to skip.
2. Color contrast: the contrast ratio between colors that performs best on a mobile screen.
3. Human expression: the facial expression that earns far more saves than a plain product shot.
4. Text overlay: where to place overlay text so it drives the most clicks.

For each point, give the rule and one concrete example applied to my niche.