That pattern is indeed odd looking.
When I run the Auto-Check pattern from the 3880 LCD display I never see Magenta nor the Yellow. I get the three blacks and the cyan, but no second row of magenta and yellow.
Usually mine will randomly drop a black or gray nozzle in first attempt at Auto, and then continues with a cleaning cycle and prints the same blacks and cyan in another stack below the above. Might be 4 stacks of blacks, grays and cyan, but no magenta or yellow ever shows up. It completes in maybe 4 attempts with cleanings, etc.
It does show the other colors in the Manual nozzle check herringbone's staggered pattern though, but the Auto on mine is a very different pattern of checkerboards with the omission of magenta and yellow.
I wonder if it could be that I'm using 3rd party inks with refillable carts, and the pirate chip over the Epson OEM chip on the refillable too?
I'm more bothered that it randomly will plug a nozzle even during a run when I run a nozzle check in between prints. Sometimes same nozzle, but lately seems random in which nozzle and color will plug and later unplug. Trying to profile is sort of iffy with the 3880 of mine. Let it sit overnight and the plugged nozzle might free. Air bubbles perhaps since the refillables do not use a bladder like the OEM carts, but I really dunno. Just write it off to being an Epson.
SG