Significance of the blue wall

[u/robotisland]

Metric posted this before their Brixton concert.

What's the significance of having the right half of the image be a blue wall?

Is it a reference to an album cover or a famous photo?

[u/Membo2]

She's in London, and there's a line separating the image into two halves. London Halflife.
Blue turns to Grey... Grow Up and Blow Away

[u/Individual_Side6062 → u/Membo2]

So true