One of the core truisms of tech is that you should take every big announcement or demonstration with a grain of salt. This tenet has now been proven once again, with the unsurprising revelation that Meta's demonstration of virtual reality legs was pulled off using motion capture technology.

Earlier this week, Meta CEO Mark Zuckerberg introduced new user avatars coming next year to the company's virtual reality platform Horizon Worlds — avatars which will include legs. Previously, Horizon Worlds' denizens were simply ghostlike floating torsos, unable to kick, jump, or partake in any other activities which might involve lower limbs.

Calling legs "probably the most requested feature on our roadmap," Zuckerberg's avatar jumped and stretched to show off his newfound limbs during the demonstration, while the ecstatic legless proletariat silently cheered for their quad-limbed king.

However, as reported by UploadVR editor Ian Hamilton, Meta has since stated that "To enable this preview of what’s to come, the segment featured animations created from motion capture."

SEE ALSO: Legs are coming to the Metaverse and everyone is...underwhelmed

In short, rather than showing off the actual tech that Meta will roll out to users, the demonstration used other tech to create a representation of what they hope to make it do. It's basically akin to Tesla's grand announcement of its humanoid Optimus robot, which was literally just a guy in a robot suit. The actual robot is markedly less limber.

As mentioned before, this isn't surprising. Anyone who's ever seen an ad will know that promotional material often uses tech that doesn't actually reflect the final product — or is even in the product at all. Still, it feels pretty misleading without any disclaimer, and could easily fool more enthusiastic, trusting viewers.

Mashable has reached out to Meta for comment.

Further raining on Meta's leg parade, others have noted that not even all of Zuckerberg's explicit claims about Horizon Worlds' updates are entirely true. Namely, his claim that "legs are hard, which is why other virtual reality systems don't have them either." Virtual reality platforms such as VRChat have had full-body tracking for years — including moveable legs. In fact, a quick search on YouTube turns up numerous videos of users using said limbs to execute some pretty slick dance moves in virtual reality.

It's unclear whether Meta's incoming legs will be capable of following users' shuffling with as much precision. But don't expect your virtual gams to be as smooth as in Zuckerberg's demonstration.