When the general practice for most remote jobs is to cut off access to all documents a few minutes after you're laid off, you do not want to be in a situation where you have to e-mail and beg someone on your former team to send you some screenshots of your work for your portfolio.
Copying company documents for your portfolio may seem like stealing from the company. So, if you're afraid of this, ask your manager (at the start of the project) for permission to put this work into your portfolio. They likely won't have a problem with...
[
add
]
[
|
|
...
]