xi ips 3 #1 vs. my new technic

i got two days free from my school. and this is the first.
so, to spend this loooooong time, im editing some of my new photo a few days ago with my classmate. and finding some technic editing from potoshop.
like this.
i made it for two colours.

 got the different?

 and these are the others..
my face looks wierd on this pictures.

 this is Mutiara, my new benchfriend

and this is my class now!!

maybe its an old technic for you, haha. am a newbie on potoshop. so, teach me! :D