What's the best way to see files of an updated git bare repository? (concept of ls-tree)

Question

I'm looking for a way to see the files on a git bare repository that were updated by other remote but without do a pull in my repository.

I'll try to describe my doubt using an example locally.

I create a folder, add two files and make a new repository.

> mkdir stackOF && cd stackOF
> touch file1 file2
> git init

Then I create a bare repository from this repo.

> cd .. && git clone --bare stackOF stackOF.git

Now I want to create two clones of that bare repo and simulate some actions of too coworkers.

> git clone stackOF.git stackOF.clone1
> git clone stackOF.git stackOF.clone2

First, clone1 will create a file, commit and push the change.

> cd stackOF.clone1 && touch file_clone1
> git add . && git commit -m "File from clone 1."
> git push

Second, clone2 will create a file and only commit.

> cd ../stackOF.clone2 && touch file_clone2
> git add . && git commit -m "File from clone 2."

At this point starts my doubt over the ls-tree concept. Executing the next command I'd expect to see the file pushed by the clone1 but I receive the following:

> git ls-tree origin
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5392    file1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5392    file2

I want to receive a result like doing the ls-tree command at the bare repository directory:

> cd ../stackOF.git
> git ls-tree master
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5392    file1
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5392    file2
100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5392    file_clone1

Studying this case, I found a command that shows me what I want but with a lot of other informations. So, returning to the clone2 and executing the command:

> cd ../stackOF.clone2
> git archive -v --remote=file:///f/gits/stackOF.git master
pax_global_header00006660000000000000000000000064133246307500014515gustar00rootroot0000000000000052 comment=0085439d6a07481e6a21db545edd3f7960c038e2
file1000066400000000000000000000000001332463075000117720ustar00rootroot00000000000000file2000066400000000000000000000000001332463075000117730ustar00rootroot00000000000000file_clone1000066400000000000000000000000001332463075000131520ustar00rootroot00000000000000remote: file1
remote: file2
remote: file_clone1

Summarizing, I'm on the clone2 repository and looking which files is on the bare repository without make a pull. But I want something much clean like using ls_tree on the bare repository.