No it's a left JOIN. Sort of.
You just need to make sure that when you're dragging your pills on to the viz that you start with the left table first making sure that it is the primary (Blue icon). The right table of the JOIN should have an orange icon.
If it's appearing like an inner JOIN then something is wrong.
I'm having a similar situation where it is absolutely acting like an inner join. here is my post:
I'm sure I'm doing something incorrectly, but I sure would like to see a left join !
It depends on what dataset is being used as the primary in the worksheet. You'll notice in the "Data" area of the Tableau canvas your two data sources. The Primary source will have a blue check box the Secondary source will have a green check box. (The secondary source will also have the "linking" icons next to the dim columns for for the data relationship.)
As a best practice, which ever data set needs to be left joined, make that be the secondary data set. Upon creating a new worksheet, I do this by dragging a dim column (usually something that will be a global filter for the workbook) into the filters pane before I start working with the secondary data set.
Without being able to play around with your workbook it's really hard to say what is happening. My guess is that you have an issue with "Brand" but I can't see how you're using brand in the relationship and how your relationship is defined. Are you able to replicate this issue with data in a workbook that you can share?
I will see if I can pull out an excerpt and put it in a seperate workbook for you. I will add it into my post.