The filter efficiency keeps improving as it gets older, until the point when it gets totally clogged up, and then the bypass kicks in. It looks like your filter medium is nicely pleated and has a huge surface area, so I would say it is probably still working extremely well. I change my filters every other time as well, I might go a max of 10,000 miles on one filter. Your drainage oil is probably a bit discolored, but still basically clean. If you have access to a microscope, it might be interesting to put a few drops
of the drained oil on a glass slide and look at it under the microscope, and then take a few drops from the dirty side of the filter and look at that under a microscope as a control, to verify that your engine oil is still being properly filtered.