As someone who has done a bit of both 1 and 2, I am just curious at to what professionals and/or hiring managers are expecting when they ask for experience in OO(Perl or otherwise).

That will be different from person to person. It will range from "Knowing arrows are involved" to "All the world is a Moose".

I wouldn't worry about such requirements in a job ad. If you want to apply and you think you've such knowledge, just apply. If they are interested in you, and want their proof, it'll come up in the process. They may discuss at an interview, they may ask for some code you've written, or perhaps they'll ask you to code something.