amp-accordion: Animated accordions containing images distort the image on collapse and don't animate on open

[andrewwatterson]

1

https://ampbyexample.com/components/amp-accordion/

In the "Animated Accordions" section:

1. Click "Section 2" to expand
2. Click "Section 2" to collapse
   Expected: Bottom border of section progressively covers image content until section is fully collapsed
   Actual: Image aspect ratio changes to fill new section size, making image distorted and looking terrible.

Observed on Chrome 71 and AMP 1901021931380.

2

https://ampbyexample.com/components/amp-accordion/

In the "Animated Accordions" section:

Click "Section 2"
Expected: Section 2 smoothly animates open like Sections 1 and 3 do
Actual: Section 2 snaps open after a perceivable pause
Observed on Chrome 71 and AMP 1901021931380.