So basically I have graphics for a die cut box, layed out flat (i'll call it file 1). Can i link that image to another photoshop file that will show it on the side of the box( file 2). So could i place file 1 inside of file 2? when file 1 is placed, it will have a perspective warp so it looks like it's on the side of the box. Is there a way to get it to auto-update? So whenever I update the graphics on file 1, it'll update on file 2 as well? Let me know if you need any more clarification.
Try the File > Place Linked command. That imports an external file as a linked graphic Smart Object, so that if you edit and save the external file, it will update inside the Photoshop document. You can apply effects to the linked Smart Object, such as perspective distortions.
If you need to manage a linked Smart Object, when it’s selected look in the Properties panel. That will show the folder path to the linked file, and let you force-update or replace it if needed.
If you duplicate a linked Smart Object, all duplicates should link to the same file already.
If you use the Properties panel to change the file that a Smart Object is linked to, all the duplicates also update to match. If you don’t want that — if you want to be able to relink each Smart Object duplicate independently — then select the original linked Smart Object and choose Layer > Smart Objects > New Smart Object via Copy.