Why do my Planetary Portals sometimes look different?

Question

While I'm playing Egg, Inc., sometimes my Planetary Portal habs change from this:

To this:

They'll stay that way for a while, and then some time later, I'll notice the entrances to the habs are back to the first style.

What's going on here?

Answer 1

If the game realises the FPS is too low then it'll change the models to a lower poly count model to help FPS.

Sorry this is a bit of a late answer but I thought I'd post an answer incase anyone else stumbles upon this question.