data.txt

721414128511212112141521311232711131213111211311141131213113111114211131251111132111121581111111111111117C1111495151121421111111631A1141121351413211112522113211A2236113342511211141113211511213411221251162232111142132313111312111124535241113123224211231321211512111122112117232412121311189221111131312117131312211113215131116231141311123111451413111212122312511311131321112222115111212111125218125521132

printer.py

import sys
data = open("data.txt", "r").read()[:-1]
even = True
count = 0
for x in range(len(data)):
   cur = int(data[x], 16)
   for y in range(cur):
       sys.stdout.write("██" if even else "  ") 
       count += 1
       if count % 29 == 0:
           print("")
   even = not even

(29 is sqrt(841), the sum of all the nibbles in data.txt)