Hi,
Looks like it’s the card wipe effect. I think the designer has made 2 flat images of everyone’s pictures in photoshop. In the example there are 16 images in x direction and 6 in y direction so assuming he used HD dimensions each little picture would be 120×180 (1920/16 and 1080/6). He would set them all out in photoshop and probably save it to one flat file (jpeg or png). He would then change the images to different people and save that as a flat file too. This will be the background of the layer when it flips over.
Bring both jpegs into after effects. create a comp 1920×1080 and drag both jpegs in. on the top layer add the card wipe effect. Make jpeg02 the background layer and set rows to 6 and columns to 16 and then play with the flip axis and flip direction.
Keyframe the transition completion from 0 to 100%.
There’s some great tutorials on the cardwipe effect here: https://library.creativecow.net/series/AE-More-Than-Transitions-Card-Wipe-Effects-with-Andrew-Devis
and here:
https://vimeo.com/34014848
Hope i explained myself ok.
Ewan