My guess is that the pictures that are not rendered are all non-working dummy devices with the screen content shopped in (the mac has some mirroring going on in the glas, the gpd does not).
If you look closely, you'll see that the grey ones aren't even labeled at all. Also, they announced updated keyboard layouts in a later update, so they likely just 3d printed some dummy caps and had only grey filament lying around.
They are showing the first(?) 'real-ish' prototype in the latest update and it's screen seems to be held together by adhesive tape on one of the pictures.

Edit: I've persuaded the server to give me a slightly bigger version of the prototype pictures.