Roleplaying in the main game is tied to some changes in Chris' scenario due to Claire's actions, whether due to items pickups, shared item box or story events. It also shows in slight changes for certain cutscenes depending on how you accomplished the previous gameplay section.
Depending on whether Claire helped Rodrigo or not, it'll change on Chris' side. If she helped by giving him a Hemostatic and her Lighter, Rodrigo will give back the lighter to Chris later on.
If Claire was infected by Nosferatu's toxic gas, Chris will need to look for a Serum when he finds her.
The Item Box is shared between the two characters.
If Claire took items or not from the enivornment will stay the same when Chris revisits the (undamaged) places.
Unlocking simple locks as Claire will have the same effect in Chris' scenario, same thing if she left the items inside. While most of their contents can be immediately used by Claire, the Shotgun Shells found in a safe in the northeast corner of the package sorting room will need to be stored for later use.
Since the Lockpick is exclusive to Claire, Chris needs to put a Duralumin Case he found in the Item Box in order for Claire to unlock it later on.