Final answer:
The Double Rainbro is not a specific flavor but rather a viral internet meme that originated from a photo of a Double Rainbow. It is part of online culture and digital art in the arts subject.
Step-by-step explanation:
The Double Rainbro is not a specific flavor but rather a viral internet meme. It originated from a photo of a Double Rainbow, which went viral on social media platforms. The meme involves people imitating the original photo and adding funny captions or altering the image in various ways.
As an arts subject, the Double Rainbro falls under the category of online culture and digital art. It showcases the creativity and humor of internet users who remix and repurpose existing content to create new and entertaining memes.