The idea of sharing unrealized projects intrigues me. Sure, in a portfolio you can choose to not mention it and most people will not care either way, but to me, there is something special about the things we create that never find their way into production. Architects seem to understand the intrinsic value of their work, unrealized or not, and it's something I admire and resonate with. Look up the project list of an internationally respected architect like Zaha Hadid and you will find many unrealized projects mixed in with completed works. I think that's nice.
For me there are two kinds of unrealized projects. The first is unintentional and most often occurs when the client's situation changes. The restaurant chain is sold back to the original parent company and they have a different vision. The new retail business hits a wall too high to surmount when the local historical society imposes preservation rules that make the project financially unfeasible. The museum decides the timing isn't right for a change. They have all happened and even though they can be a bit of a surprise, they are often not a very traumatic experience and just part of the way things are. You move on to other projects but there are often interesting concepts in the archived files.
The second type of unrealized project is intentional and they can be rewarding from a creative experience and highly beneficial for the client. These are projects whose intention is to deliver ideas in the form of freeform visual concepts. The deliverable is not a billboard or logo or website but instead a set of thoughts, visual cues, and proto-designs that are free of the constraints of specs and medium. At times it is a type of freedom that borders more closely to fine art. These projects often set the rhythm for another team of creatives (often internal) and I think it's probably freedom for them, too, as they are given something to work from but are free to express their own vision, as well.
I've been fortunate to have worked on such projects throughout my career and count every one as a gift within a field of natural commercial constraints. Within this portfolio of work you will find several unrealized projects, many of which I value as much as the projects that eventually passed through a Heidelberg printer.