https://www.legacysurvey.org//viewer/?ra=61.1884&dec=-47.5005&layer=ls-dr10-south-resid&zoom=9
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Oh, you’re on the residuals layer. This is basically just the difference between the model layer and the actual science layer. Doesnt surprise me that it looks weird.
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On zoom 12 and below, parts of real images only show up, but zoom 13 to 16 are normal, then whatever it is certainly a glitch in residuals 
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Well then whatever it is amost certainly it is
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What actually is the residuals layer? “Difference between model and science” what does that mean?
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Basically DESI has attempted to fit a model to the imagery that it has collected. But the model is pretty simplistic and tries to model most things as simple elliptical galaxies, which is fine for the distant galaxies that are relevant to their science goals, but is pretty bad for nearby non-elliptical (e.g. spiral, irregular, etc) galaxies and other types of object.
The residuals layer is basically showing you the difference between the model and the actual imagery. So its a measure of how effectively the model has been fit to the data, and shows which parts of the data it wasn’t able to model well.
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