Why does my new "Portfolio" home page look scattered from some computers?

Hi all,
I'm just starting to build a website using the Portfolio theme and if I navigate to the domain from my home computers I see the landing page with no problems in Chrome and Edge. (Windows Explorer as a few strange triangles that show up black instead of white). But more importantly, when I navigate there while I'm at work on my work PC (when I should be working, :-) ) I see a very scattered landing page. It almost looks like it is trying to view the site as a mobile device. Interestingly, if I move off of that home page into the "portfolio" page, everything rectifies and looks good again.

Does it look scattered to anyone else? http://www.kehnindustries.com
I haven't been able to duplicate the problem at home, on my home PCs, even though I've cleared my browsing data.

Do you know where I should start, as I try to trouble shoot this?
Thanks for any help you can provide,
Brian