It takes about a minute. Pick a picture, the game finds the faces in it, you give them names — and from then on they are the invaders.
The Studio. Tap a face to preview it on the invader, hold to remove it.
When the library is full the game stops accepting new faces until you remove one. Removing a face also deletes the copy stored on your device.
Twelve. Since one picture can contribute up to six faces and you can pick four pictures at a time, the library fills up fast. Hold a face in the Studio to remove it and make room.
It falls back to a square crop from the middle of the picture and offers you that instead, so you still get an invader out of it.
Yes, and that fallback is exactly why. Detection is looking for human faces, so a dog or a doodle usually falls through to the centre crop — which works fine as an invader.
Press and hold it in the row of faces in the Studio. The face goes, and so does the copy of it stored on your device.