There's not much to use to compare scales in this shot alone, so it looks like Lilith's head is garguantuan and resting atop a pile of Eva-sized bodies. But then I wondered what would happen if you compared this shot to the shots of Zeruel staring down the bridge, and the quick skirmish with Eva 01 that followed.
Zeruel's second form is bigger than an Eva, but it's crouched down when it enters the command center. This puts the operations deck where Misato/Ritsuko/the three bridge bunnies are right at face level for it:
Then Unit 01 does us a solid and provides an excellent size reference for the bridge:
Unit 01's crouched and leaning forward, but it looks like the operation deck would be just a little under chest height if it were standing up straight.
According to this, that puts the deck at a height of around 60 meters:
If you look at the first image again, you can see the operations deck over on the right, and the two empty lower levels where the Magi should be. Lilith's head isn't all that big when you compare the two. In fact, it doesn't look like it's as tall as Unit 01! That also means the pile of FoIs beneath it are actually fun-sized Evas! Maybe 1/2 to 1/3 scale? It's hard to tell exactly where the floor is in any of these shots.
Evidently her body continued to grow long after the head came off. Mark.06 is tiny compared to the rest of Lilith's enormous body and it's about 3 times bigger than a normal Eva when it's all bloated up, and much larger than the head would be.
What do you all make of this? We already knew the FoI could be Eva sized and super sized, but apparently they can also be snack-sized too! And what about Lilith's body? It lumbering around headless doing whatever isn't completely out of the question in this continuity. Or maybe Mark.06 was controlling it before they were skewered and left to rot?