It's not necessarily unheard of. People who work at architecture firms routinely having portfolios of stuff they've worked on. If you don't have a portfolio of work from previous employers handy, what is in your portfolio? And if one doesn't have a portfolio of demo code that showcases style and experience and skill, one doesn't really get to complain that someone else doesn't have context to judge appropriateness for a job, or that they are expecting some context to be able to make an informed judgement.