TMR put this up on their Facebook asking who has to give way, but that's too easy. A much more complicated question is: what does the law say around indicating?
I've seen people say only blue must indicate, others say both must indicate, and yet others say neither must indicate. Which is correct?
Here's a relevant TMR section on the website to do with merging in these situations. Noticeably (and it's more apparent in the video), they only ever show the car in the left lane indicating.
https://www.qld.gov.au/transport/safety/rules/road/lanes
What they show in pictures is not what's written in the law. It wouldn't be the first time TMR's interpretation in supplemental material misunderstood the law.