https://www.pcgamer.com/gearbox-teases-more-secrets-hidden-in-the-borderlands-3-cover-art/

Some interesting hidden messages and Easter eggs have been found buried in the Borderlands 3 reveal art, but Gearbox says there are still some that haven't been found. To help internet investigators get on with the job, and remind everyone about the gameplay reveal stream coming on May 1, it's shared a high-resolution image of the image "as a hint" for internet investigators. 

The image is 4417x5528, so you can get a good, up-close look at everything, and contains the Morse code message discovered last week that hints at the return of the Destroyer—noteworthy because the code was absent from previous Borderlands 3 key art. And just like those messages asked rather than answered questions, Gearbox effectively stated that anything you manage to unearth from this image will probably keep you guessing until the gameplay reveal.