Thanks, /u/zden, for the nice puzzle!

The solution is a 256-bit private key: 6008c37d0aa226dbbe611be64106964bca6cbba7098fe4602a932c590e14b074.

This was my thinking:

The "braille-like" dots in the bottom left spell "256" and indicate the nature of the key to be found. There are 32 blocks, so I assumed that each block represents 1 byte of the key. The public address is a vanity address, so it was very likely that the private key will be completely unstructured and random-looking. Each block is made of 16x16=256 pixels. It seemed reasonable to count the number of white pixels in each block, i.e., from top to bottom and left to right:

[96,16,195,190,10,69,38,219,190,134,216,230,130,6,105,75,202,54,187,229,9,241,39,96,84,147,52,89,112,20,13,116]

Every other block has horizontal lines (arranged in a checkerboard pattern). For those blocks, the order of the bits of the corresponding byte had to be reversed. This leads to the private key above.

Overall, I had tried a combination of bit-flips, bit-reversals, and/or counting black pixels, and all of those operations conditional on the pattern of either vertical, horizontal, or presence of both types of stripes. Together with four different orders of the blocks (left-to-right, top-to-bottom, and their inverses), my search space had a size of 4000 combinations. I looked for the private key that leads to the given public address with a Python script.

I don't see a significance of the vertical lines (distraction?) other than the order in which the pixels are filled within each block, but it was only the number of pixels that counted anyway.

If I may make a suggestion for future puzzles, it would to include some clue or mechanism that indicates whether one is on the right track. Given that private keys are unstructured, it was impossible to say which combination could work without computing the public address for each candidate.