Whatever visual illusions were present (and there are some pretty convincing ones around), to touch down on the very beginning of the paved surface after hitting the ILS antenna and some of the lighting, their aiming point must have been well short of the runway, i.e. a visually obvious undershoot.
It’s possible there was some last-minute windshear as there were TS around but apart from that, I would guess that one or both of the pilots could see they were undershooting but for some reason did nothing about it. It could be that they had still had FDs on with inappropriate guidance or this was a cockpit gradient/CRM issue (not unknown at THY). Why they didn’t correct an unstable approach or even GA will hopefully be addressed in the report...