Steps to replicate the issue (include links if applicable):

• Visit https://test.wikipedia.org/wiki/World (on mobile skin, as a logged in user with the carousel beta feature enabled)

What happens?:
The first image in the carousel is different from the first image in the article body. See the screenshot below:

What should have happened instead?:
The first image in the carousel should match the first image in the article body (the image of the Earth in this case)

Additional notes

Under the legacy parser, loading the MMV ligthtbox when clicking on a carousel image currently fails due to T427542. However, with Parsoid enabled, it is possible to see an additional aspect of this image ordering bug. Repro steps below:

Steps to replicate

• Visit https://test.wikipedia.org/wiki/World?useparsoid=1 (again, on mobile skin, as a logged in user, with the carousel beta feature enabled)
• Click the first image in the carousel (which is Mercury, not Earth)

What happens
You can see the MMV lightbox open, displaying the Mercury image. The counter says "3/9".