The clues for the safe combination can be found in the wall next to the door

-You Spilled message on the mirror/picture
-Gun permit
-The picture of the couple

So the sollution is really simple!

In the safe put the following code

-Milk
-Gun
-Sorrow

And that is all you will unlock it and you can grab the picture

P.S There is another picture in the room. You should pick up the tea cups and put them all together!

Thank you for reading this guide! Hope you have found it useful!