Photon: Test handling of big images

[kraftbj]

Flyby to investigate the handling of big images in 5.3: https://make.wordpress.org/core/2019/10/09/introducing-handling-of-big-images-in-wordpress-5-3/

Make sure we are compatible (should be I reckon) and see if there are any optimizations we can add for those on 5.3.

Master issue: #13597

[kraftbj]

Some discussion at p9dueE-13w-p2 . The "full" image would change with 5.3 that we pull since the filename format is different than most resized images. Need to decide which way to go.

[kraftbj]

Related in 2659499-zen, we should examine whether the usage of the theme's content width (specifically the default of 1000px when none is set) is still needed in today's Gutenberg full-width era.

[jeherve]

we should examine whether the usage of the theme's content width (specifically the default of 1000px when none is set) is still needed in today's Gutenberg full-width era.

Related: #4175

[stale]

This issue has been marked as stale. This happened because:

• It has been inactive in the past 6 months.
• It hasn’t been labeled `[Pri] Blocker`, `[Pri] High`.

No further action is needed. But it's worth checking if this ticket has clear reproduction steps and it is still reproducible. Feel free to close this issue if you think it's not valid anymore — if you do, please add a brief explanation.