Looks like a cottage cheese yeast shake!
Just like Hammy said, what you're seeing is perfectly normal for a starter with WLP002/WY1968ESB.
Watch your ferment temps carefully with this strain. Start it at 63-64*F. When it starts to slow down, bump it to 65-66. A few days later, raise it up to 68-69*F until finished. If it stays too cool after activity slacks off or if you have a temp drop, it will fall out of suspension prematurely and form the most solid, rubbery yeast cake you've ever seen. You'd have to rouse it with a sanitized spoon since swirling won't even budge it.