Video Thumbnail Generator (Long + Short Form)

Generate professional thumbnails and vertical cover art using Gemini Nano Banana Pro. Produces 4 entirely different concepts at once, saves them individually, and creates a 2x2 comparison grid so the user can quickly pick the direction they like best.

This skill handles both:

• Long-form (horizontal, 16:9) — YouTube video thumbnails
• Short-form (vertical, 9:16) — YouTube Shorts, Instagram Reels, TikTok cover images

Step 0: Ask Which Format First

Before anything else, ask the user exactly this:

Long-form or short-form?

• Long-form → 16:9 horizontal YouTube video thumbnail
• Short-form → 9:16 vertical cover image for Shorts / Reels / TikTok