Fabric Deployment Pipelines

I am exploring fabric from data science point of view and was working on deploying sample project to test and prod stages. In my sample solution I have notebooks, data pipeline and lakehouse. When I deployed the solution to test, I deployed these three items. Then when I opened the notebook in test workspace, I see a lakehouse attached to that notebook and I can see all the data in that lakehouse from the side pannel of notebook.

But when I open the lakehouse in a new tab or you can see in explorer, I don't see any data there.

Now in the first image, when from the side pannel I deleted one table in test workspace, the table got deleted from the lakehouse of development workspace as well.
When I deployed the solution to test stage since my lakehouse also got deployed to test stage, I though the lakehouse would have been cloned/copied to tests stage/workspace as well and that both workspaces would have their own copies of the lakehouse. But this does not seem to be the case.

Now here is what the documentation says:

When you deploy content from one pipeline stage to another, the copied content can contain the following items:

• Data pipelines
• Dataflows Gen1
• Datamarts
• Lakehouse
• Notebooks
• Paginated reports
• Reports (based on supported semantic models)
• Semantic models (except for Direct Lake semantic models)
• Warehouses

The following item properties aren't copied during deployment:

• Data - Data isn't copied. Only metadata is copied

Now it says that "Lakehouse" is a supported item but data is not copied. So then what exactly is being deployed to test stage/workspace. Because when I open the test workspace I see all of the contents there e-g:

So in test workspace the same lakehouse appears as we had in the development workspace, so when the documentation says the "data is not copied", so what exactly does this lakehouse represent here?

Just to summarize the question is "When we deploy from one stage to other and we deploy lakehouse as well, what exactly is being deployed, because we can see the same lakehouse in test stage after deployment, so is it just a pointer over the development lakehouse or what?"