How does Azure Blob Store treat files ending in .gz?

Question

I have a file named notactuallygunzipped.gzthat is a plain text file that happens to end in .gz and is NOT actually gunzipped that looks like so:

1 foo bar
2 fizz buzz

I upload it to Azure like so:

az storage blob upload \
  --container-name testroot \
  --file notactuallygunzipped.gz \
  --name "gunzip/notactuallygunzipped.gz"

I then use the Azure Go SDK to fetch the blob. I'd expect to get back something like 1 foo bar or whatever in byte format, but instead I'm

\x1f\x8b\x08\x08\x9d\xfa-Y\x00\x03notactuallygunzipped\x003TH\xcb\xcfWHJ,\xe22RH\xca\xccKWH\xca\xcfK\xe7\x02\x00\xa5\x00\xef\x1e\x16\x00\x00\x00

If I rename the file to something like plaindata.txt it works fine and I get what I expect:

'1 foo bar
2 fizz buzz
'

Does Azure do something wonky? Either automatic compression or something along those lines?