A style reference is the bridge between your input and every icon you generate. It's what makes the output feel consistent rather than random.
When you upload an image and circle shapes, the AI extracts several properties: stroke weight (how thick or thin the lines are), fill style (outlined, filled, or mixed), color palette, and a set of qualitative descriptors — vibe tags that capture things harder to measure numerically.
Stroke weight is probably the most important. A 1.5px outline icon and a 3px filled icon look like they come from different universes, even if they depict the same object. Getting this consistent is what makes an icon set feel unified.
Color is more nuanced. If your reference uses a deep navy and warm white, the generator doesn't just copy the hex values — it understands relationships. Foreground vs background. Accent vs neutral.
The vibe tags are where it gets interesting. Terms like 'geometric', 'organic', 'technical', 'playful' shape the overall character of what gets generated. These come from the shapes you marked, not from anything you had to describe.
You can also edit the style reference directly — adjust stroke width, swap colors, update the tags. The reference is a starting point, not a constraint.