Small pics collage projected on face effect

1. ASSEMBLING THE THUMBNAILS
Start by creating a new file. Insert an image. Scale down the image to the thumbnail size.

Similarly insert more images and scale down to equivalent sizes.

Once whole canvas is filled up with thumbnails of various images, flatten the image.

2. GETTING A FACE TO PROJECT THE COLLAGE
Open another image of a face closeup.
Select brush tool with feathered brush settings . Select black as foreground color and cover the hair area.
3. CREATING PROJECTED IMAGE EFFECT
Drag the merged images file to the main file. Scale down to the document size and change the layer mode to overlay.

Press Ctrl+T. Right Click and select Warp. Adjust the nodes to get the face shape as shown.
Select eraser tool with feathered brush settings and remove the eyes, nostrils and lips area.
Drag the merged images file to the main file. Press Ctrl+Alt+G to create a clipping mask. Change the layer mode to "Linear Dodge".