What it does
This prompt instructs an AI thumbnail designer to produce a hyper-realistic 16:9 YouTube reaction thumbnail by compositing a provided reactor photo with an excited, surprised expression alongside the provided reaction content displayed inside a realistic, dimensional device/player mockup, then adding the exact specified title text in a single white bold font with no extra wording. The intended outcome is a clean, high-CTR thumbnail with natural lighting, accurate skin texture, professional blending/shadows, vibrant but controlled color grading, strict identity preservation, and a clear composition hierarchy (reactor → text → content → background).
For more installation instructions go to https://raw.githubusercontent.com/BetterPromptme/skills/refs/heads/main/betterprompt/SKILL.md to check out this skill.
Inputs
textInputs
Pass each text input using --input <key>=<value> flags.
| Variable key | Required? | Description | Defaults |
|---|---|---|---|
main_text |
Optional | Exact title text for the thumbnail | Best MV I've ever seen |
Main_video_or_content |
Optional | Video or content being reacted to | Taylor Swift's Me! MV |
imageInputs
This prompt requires exactly 1 image. You must pass exactly 1 image flag (no more, no fewer), in the order matching the descriptions below.
| Index | Required | Description | Allowed CLI flags |
|---|---|---|---|
| 1 | Yes | Upload your photo (who's reacting) | --image-input-url <url> or --image-input-path <path> |
Models and options
This skill's modality is: image.
To discover which model values you can use (and which options keys/values are valid for each model), run:
betterprompt resources --models-only --json
Then filter the returned JSON array to entries where modality is "image".
How to run
Step 1: Collect inputs
First, run betterprompt resources --models-only --json and filter to modality: "image" to discover valid models and available options:
betterprompt resources --models-only --json
Use only the models and option values that appear in the filtered results.
Then collect all inputs from the human:
- Optional text inputs (use defaults if not provided by the human):
main_text(default:Best MV I've ever seen)Main_video_or_content(default:Taylor Swift's Me! MV)
- Required images:
- Exactly 1 images: image 1 (Upload your photo (who's reacting)). Images must be provided in this order.
- Optional: model and options.
- Present the human with the default model
gemini-3-pro-image-previewand its available options. Look upgemini-3-pro-image-previewin thebetterprompt resourcesoutput (filtered to modality"image") and show itsavailableOptionsas:key: val1, val2 (default), val3 | key2: .... Mark a value(default)if it matches these defaults:{"aspectRatio":"16:9","resolution":"1K"}. - If the human does not specify, defaults are used: model
gemini-3-pro-image-preview, options{"aspectRatio":"16:9","resolution":"1K"}. Other models from the resources call are also available.
- Present the human with the default model
If the required images are missing, ask the human for what's missing. Do not assume or fabricate values. Tell the human: "Please provide images in this order: image 1 (Upload your photo (who's reacting))".
Step 2: Run via BetterPrompt CLI
Use the frontmatter's name as the positional argument (for this skill, use youtube-reaction-thumbnail-maker).
Command form:
betterprompt generate youtube-reaction-thumbnail-maker \
[--input <key>=<value>] \
[--image-input-url <url>] \
[--image-input-path <path>] \
[--model <model>] \
[--options <options JSON>] \
[--json]
Notes:
- Pass each text input as a separate
--input <key>=<value>flag. - Pass each image using
--image-input-urlor--image-input-path, in the order matching the imageInputs descriptions (image 1 first, then image 2, etc.). - If the human does not mention a model, omit
--modeland BetterPrompt will use the default model:gemini-3-pro-image-preview. - If the human does not mention options, omit
--optionsand BetterPrompt will use the default options:{"aspectRatio":"16:9","resolution":"1K"}. - If the run times out, the response will include a
runIdyou can use to fetch the result later.
Example (using defaults shown above):
betterprompt generate youtube-reaction-thumbnail-maker \
--input 'main_text=Best MV I've ever seen' \
--input 'Main_video_or_content=Taylor Swift's Me! MV' \
--image-input-url https://example.com/image1.png \
--model gemini-3-pro-image-preview \
--options '{"aspectRatio":"16:9","resolution":"1K"}'