Thanks for the link, I found it on Instagram:
Really hard to tell where the runway ends but the cloud of dust looks very similar to times that airplanes haven't lifted off until the very end of the runway, blowing dirt and dust that usually is undisturbed.
That airport has a very long runway, however the full length requires a taxiback and turnaround at the northern end. While it's common in the US to depart from a taxiway intersection rather than the full length of the runway, typically this sacrifice is only a few hundred feet, not a few
thousand, and crews will have either briefed it already as they know their takeoff length requirement, or be briefed by ATC and then make the decision whether or not to accept the intersection departure. But I highly doubt their SOP allows them to accept an intersection departure from literally half of the runway length.
Something about that climb and descent looks like a thrust issue to me. I can't think of anything right now that wouldn't set off alarm bells in a Bombardier and that 787 is even more automated with a very integrated EICAS message system.
There have been instances before of jets attempting takeoff without flaps, however if I remember right in those cases the airplane rotated and attempted to climb at a normal flap speed except without the flaps which simply won't work. Modern computers calculate these differences. This plane did achieve rotation speed and an initial climb but then just stopped climbing.
I also note that the gear was still down and doesn't appear to be transiting - I assume the 787 still uses the manual "positive rate, gear up" callout and action, and that happens within seconds of liftoff, literally as soon as the FO observes a positive climb rate. But while the landing gear being down does increase drag and slow the climb, it doesn't
reverse the climb, not even close. Most transport jets are certified to fly at 250kt and 18,000 feet with the gear down in case of a maintenance issue, and can obviously takeoff and climb with plenty of power despite the gear being locked down.