I've been asked to give a seminar at an other research center about my work. Specifically about a device which was installed in an experiment.
I have an early prototype of it (Size is about 20x5x2 cm). The prototype was and never will be installed and as such safe for people to touch it.
I was pondering to bring it along flashing is shortly in front of the audience for them to better visualize it when I go over the layout of it. After that I would leave it on the table during the talk, as not to distract the audience by circulating it, and let everybody who's interested come to have a look afterwards. There is no subsequent speaker after me.
I was wondering if this is a good idea or considered unprofessional, since showing the device doesn't add any content per se (as it is too small to see for the audience) and only tries to engage the audience.
The goal of your seminar is to educate and inform your audience about your work. If showing the audience a prototype of your work will help them to better visualize and conceptualize what you are doing, then why wouldn't you want to take advantage of that during your talk?
So long as you properly integrate into your talk—make it an essential part of it, rather than just "for show" while you talk—then the prop will do its duty.
What you might want to consider is taking some high-quality photos of the prototype that you can show on the screen as you talk about the prototype while holding it. Then you can get the best of both worlds.