I was thinking of this:
Where it does look like the nacelles and outer engines are raised a bit to adjust the clearance, but I'm fairly sure they're actually static.
Because at that point, the design still had the wings straight across the top.
Which in the final design would look like this:
As opposed to what we actually got, namely the wings sloping downwards like this:
So as far as I can tell, the engine pots are static in all of these concepts, they only adjust based on the angle of the entire wing.
But even so, the engines always looked like they were on hinges, so it's entirely possible this was intended and simply never realized.

Where it does look like the nacelles and outer engines are raised a bit to adjust the clearance, but I'm fairly sure they're actually static.
Because at that point, the design still had the wings straight across the top.

Which in the final design would look like this:

As opposed to what we actually got, namely the wings sloping downwards like this:

So as far as I can tell, the engine pots are static in all of these concepts, they only adjust based on the angle of the entire wing.
But even so, the engines always looked like they were on hinges, so it's entirely possible this was intended and simply never realized.