It is a Linux machine. Runs a Debian derivative, and it's not like Windows or anything else that isn't Linux/BSD can run on a RISC-V laptop.
This isn't the first RISC-V laptop, but the significance of a RISC-V laptop existing is primarily for developers who work on software targeting RISC-V systems. The ability to run RV64 programs without emulation and to natively compile RV64 software without cross-compilers is valuable to some people. Also, China in particular sees value in having computing products that aren't affected by sanctions; the processor in this is designed and manufactured by a Chinese company without licensing any intellectual property from US or UK.
Explaining what RISC-V is
RISC-V is a relatively newer CPU instruction set architecture that competes with x86 (Intel, AMD) and ARM (Qualcomm, Ampere, MediaTek, etc.). Its current designs don't really match those two in general-purpose performance yet but has the distinction of being a free, open, and extendable standard. Whereas x86 has only two CPU vendors and ARM has many vendors who all need to pay per-core license fees to ARM Holdings and have limits imposed on what they can do to it, RISC-V processors can be made by any hardware vendor with the means to make a processor and can be custom-designed to better fit specialized use-cases. Its use in general-purpose CPUs is catching on fastest in China but it sees use across the world in academia and in special-purpose processors by companies like Western Digital.
Even their earliest "uncarrier" features weren't without issue. Making certain services (spotify, apple music, youtube, netflix, etc.) not count against subscribers' data caps, while continuing to enforce data caps for other uses, goes against the spirit of net neutrality. This also includes throttling video streams by default to force lower quality (with opt-out on their site).
Promos like a free pizza on Tuesdays seems like a neat optional perk on the surface but their existence fundamentally mean subscription expenses on cellular network service are partially going towards things that have not even the slightest tangential connection to the service.