Social Thumbnail Workflow

Generate cover art for short-video platforms (TikTok / Reels / Shorts) or vertical social feeds. Optimized for 9:16, high contrast, big-headline space, and 1-second feed legibility.

When to trigger

• User says "video thumbnail", "封面", "短视频封面", "Reels cover", "TikTok cover"
• User mentions "9:16" or "vertical poster" or "竖版海报"
• User describes content meant for mobile feeds and asks for visual

Design constraints (apply to every prompt)

1. 9:16 aspect ratio — pass aspectRatio: "9:16" explicitly to every generate_image call. Do NOT write --ar 9:16 in the prompt.
2. High contrast — bold foreground subject against a strong color-block or gradient background. Tiny details get lost when scaled to a phone-feed thumbnail.
3. Headline-friendly composition — leave a clear zone (top third or bottom third) for the user's title text. Mention this explicitly in the prompt: "leave top third clear for headline overlay".
4. One focal point — feed thumbnails work when the eye lands in <1 second. Don't pack multiple subjects.
5. Brand-safe color — when the user gives a brand color, pin it; otherwise default to high-saturation primary palettes (red / cobalt / orange / electric green) over muted tones.

Workflow