証明写真 - "Shōmei shashin." This is another very common photo term in Japan. You often see it at camera shops, photofinishers, and on these photo booths.
This booth is emblazoned with "Shōmei shashin" in red characters. It means ID photos (for resumes, driver's license application/renewal forms, and passports). Of course, people often use it for fun too.