OpenMV has a couple of pins that you can use for connecting servos (for example, if you want to mount it on a pan-and-tilt base), but you can't use those if you also want to use the WiFi shield or any other shield that uses up a lot of pins. Practically the only pins left to use are the I²C ones.
This is again the same as the 16-channel version of #Servo Breakout for WeMos D1 Mini and as the Adafruit 16-channel servo board -- it's just in a more convenient form factor that plugs directly into the OpenMV board. Due to space constraints, there are only 12 servo plugs -- the remaining 4 PWM outputs are broken out as a 1.27mm-pitch header. There is one address jumper exposed, so you can stack two such shields.