Remember soldering in that blue potentiometer? You can twist that to adjust the 'speed' of the POV effect. Depending on how you are doing your light painting you can adjust it up and down.
The chip in the MiniPOV4 is programmed with a USB bootloader that looks like a USBtinyISP. That means: if you are an advanced user you can use the bootloader with avrdude or Arduino IDE and selecting USBtiny as the upload protocol!
The EEPROM section of the chip is what holds the 'image', the firmware is in "Arduino-ese" and can be adjusted and reprogrammed by selecting USBtinyISP as the programmer and holding down shift when clicking upload