Here is another optical illusion humidifier that gives the illusion of water droplets flowing upwards as you turn it on. The Winben Anti Gravity Water Droplet Cool Mist Humidifier uses ultrasonic technology with high frequency vibrations. It has a noise rating of 25dB.
This humidifier automatically turns off after 4 hours. It also monitors water level and lets you know when you need to add more water. You can find out more about it here.