Power BI - Cardinality Swapping (Xpost from Reddit)

I'm very familiar with database relationship structure. I may get some of the terminology wrong, since I'm mostly self taught, but this is how I generally understand it:

When you're describing the cardinality between two tables (1:1, 1:*, *:1, *:*) the left hand value is the primary table and the right hand value is the secondary table.

For example, you have two tables:

1. A dimension table of employees with a primary key of employee ID

   1. There is only one entry per employee

   2. This should be your "Primary table"

2. A fact table of employee logins/logouts to a particular system with the employee ID as the foreign key

   1. This should be your "Secondary table"

3. Their relationship would be denoted as one-to-many [1:*]

   1. One entry on the employee (primary) table links to many entries in the login/logout (secondary) table

This all makes sense in my head. However, when I establish relationships in Power BI, it seems to reverse the cardinality to read [secondary:primary]. In this case instead of the commonly agreed upon notation of [1:*] Power BI will change it to [*:1]. Is this a bug or a feature? If the latter, why would they do this? Or am I misunderstanding how to denote database/table relationships? Any insight is appreciated!

I've set up this Cardinality in every way imaginable, but it always displays [secondary:primary]. It doesn't just happen to the relationship between these two tables. This doesn't appear to affect the actual behavior of PBI, but I am writing an SOP for my company and need to be able to address the behavior.

Update: It appears Power BI uses Star Schema