# Does data entropy depend on the arrangement of the characters in a file?

From what I understand data entropy controls the limit of data compression and it depends on the probability of the characters in the file. Assuming that we have a file of size 256 bytes containing 256 different symbols and we made a bigger file consisting of many copies of that file, And because the small file has the maximum entropy a file of its size can have, the big file will also have that high entropy (because all characters have the same probability). Although that file has high entropy it still can be compressed to a very smaller size. What did I misunderstand here?