The original phrase "No images?" is too direct, giving an abrupt impression such as "Don't you have any image files?" ("画像持ってないの？") for Japanese. Instead, I refined it to "Don't you have the image files you want to use for the trial?" ("ダミー用の画像がお手元にない？") to provide better context.
Applied translation that "Great for quick prototyping! 🧪".
lang/ja/sprite.md