This is a project I’ve been working on for some time now; It contains a Pi Zero, a thermal printer that can print stickers, a pi camera, a 1200mah 2s lithium-ion battery, and some power circuits.
A short press on the green button takes a picture, by rotating it you can adjust the brightness of the picture, and a long press prints the picture onto the sticker paper.
https://blog.adafruit.com/2025/04/18/pi-zero-powered-instant-camera
https://www.reddit.com/r/raspberry_pi/comments/1jmpz4w/i_made_a_pizero_based_instant_camera/