Where's the yeast?

Recently washed wyeast 1028 London ale from a robust porter I brewed a month ago. Can't seem to separate the yeast from the rest (pictured) even after repeating the washing process. I've done this three times successfully from other batches, but they were lighter beers, so I'm wondering if the yeast is just "hidden" because of the darker trub from the porter. Take a look and tell me, would you pitch it or dump it?

Can't help with the photo, I can't tell either. But did want to share that I don't reuse yeast from batches of higher gravity beers, say 1.060+, as your robust porter might have been, under the theory that higher gravity beers stress the yeast. Typically, I'll reuse the yeast from a lower gravity beer to make a higher gravity beer - reuse the yeast from a cream ale to make an American IPA, for example. And when I to that, I usually don't wash the yeast.