Is it possible to add non-existent companies to the portfolio (landin pages)?

Question

Portfolio

Actually the question is: Is it possible to add non-existent companies to the portfolio? After all, for the customer, for whom I will provide a portfolio, it is important how the site is laid out and the code itself (working example), and whether this company really exists. Or shouldn't it be done?

Answer 1

What difference does it make if you did it, you show your work, what you did and what you can do, your style.

Answer 2

You should not do this (substitute non-existent companies), because the completed project is not only a working example, but also interaction with the customer.
Show your work as simply done, not custom-made.