It's something similar like Google's ReCaptcha. For most of people it doesn't makesany problems to solve it, but when people were using it a lot on faucets, difficult of captcha become very high and it took a while to solve it.
Since Freebitco.in introduced Cloudlfare, made already quite a lot claims from faucet, but so far didn't had to solve any captcha.
For hourly claims, the CAPTCHA won't really treat you as a bot. However if it involves multiple times within a short span, they will start throwing challenges.
I'm getting my premium wof spins, they're paying 4 or 5 times daily to compensate those days that we didn't receive any wofs, this is great.
Nice, about time!