harvested yeast question (brewing today)

I took this yeast from the carboy on the 11th of March.
I swirled the yeast cake with some boiled and cooled water
and dumped into sanitized jar, and put it in the fridge. I did not
do any other rinsing of the yeast. It is WLP 007 Dry English.
I was planning on making a small starter to get it activated.
Looking at this sample you can see a small thin layer on top.
Is that the yeast and the rest all trub? If that thin layer is the
yeast it won't be enough and I'll have to use my back up dry
yeast pack.

Thanks
Dan

the stuff on top is your most viable yeast at the time butit's probly not the only usfull yeast in there. then washing yeast they do it twice teh first time gets most of the trub and junk out. then you drain the water off that water have the suspended yeast in it and you let that settle out. This does not leave lots of yeast and you can make a starter with what you have but i would wash it again first.

If it were me, I'd just decant most of the liquid, shake it up and pitch the whole thing.

it is fairly unlikely that pitching it all will change the beer. uless you are making a very lite hopped beer. but a starter is almost always better