The monkey is a tribute to Jack. Both monkeys and the orange have meaning:

@jack is the monkey on the right. The monkey on the left represents the world 🌍, especially present/ future users of BTC + Nostr. The orange 🍊 represents Bitcoin and the virtue of generosity. @jack’s hug is inspiring the other monkey 🌎 to reach out to the orange 🧡 and pass on the love of BTC through giving—all made possible by the Nostr protocol.