So pretty... on paper
One of problems manufacturers face when designing systems to look pretty is, well, reality. Take my, for example. It's intended to look sleek and relatively invisible, but that's only true if you don't need to get to the connectors on a regular basis and can place it with its back to the wall. But I do need to get to the connectors almost daily, so mine has a rat's nest of cables pooled on my desk in front of it with a hub hanging off because it doesn't have sufficient USB ports, either.
The Slice isn't quite as bad, but sadly doesn't look nearly as nice in the real world as HP's marketing photos would have you believe. It's got a power button, charger connection, Ethernet jack, USB-C and two USB-A connectors, DisplayPort and HDMI for connecting to a display, and Kensington lock slots on each module. On the side is a headphone jack and Thunderbolt-compatible USB-C connector.
First, none of HP's photos show it with the power cord hanging out the back; they show it elegantly perched, isolated on a desktop, somehow operating without a power source. Using a compatible monitor -- that is, one with a USB-C/Thunderbolt port that outputs sufficient juice (and HP just happens to have one!) -- you can power the desktop and a single module via the display, which would look a lot more innocuous.
To connect a display, you can use that USB-C port, but most people will likely need to connect via HDMI and/or DisplayPort. The 4K output will look lovely onscreen, but those huge connectors out the back? Not so much.
Then, of course, there are the inescapable and usually nonremovable stickers plastered on the front. Those don't appear in the marketing photos either. Ugly -- and they should be on the bottom of the system. But then you might forget Intel's Inside or that the system's certified for Skype for Business! The horror!
And there's the phone. The touch controls let you adjust volume in any application, much like the B&O implementations onand all-in-ones. The phone controls, though, can only operate when using a Windows application (because they work via a Windows application programming interface). So if you're using a web-based interface for something like Google Hangouts, no go.
If you're teleconferencing via Wi-Fi, what people hear from you on the other end isn't great, either. The mic is very good -- you can tell because recording directly on the system sounds great. But by the time the sound has been chewed up and compressed to pass through wireless connections, you really don't gain much. It should be better over wired Ethernet which is likely in an enterprise setting but probably not as common in a home office. And that's another cable hanging off your Slice.
Any way you Slice it
It's not as generally useful as I'd like or as unequivocally attractive as other HP system designs we've seen of late, though it does use the same brown-and-copper color scheme. If you spend a lot of time on calls and are enmeshed in a Microsoft ecosystem -- you use its applications rather than, say, web-based Google ones -- and want a desktop system that's smaller than any laptop, the Slice is a good bet. It's definitely attractive as well, but don't count on it remaining quite so sleek after you've hooked it up.