Bizarre krausen

I’ve got a secondary krausen going on that’s got a funky patch in the middle of it that sits lower than the rest of the krausen. It’s got an oily sheen about it and it’s darker. I figure it’s fine, but it’s impossible not to fret about it.

Side notes: it’s a double IPA, I added a lb. of table sugar dissolved in 20 oz. of boiling water just after transfer to the secondary. I also raised the ambient temperature over the last four days from 64F (where it’s been fermenting for over two weeks) to 70F. I know this accounts for the krausen, but I’m worried about that little funky oily circle.