FSE NUX: fix the dimensions of the preview image

[ramonjd]

Changes proposed in this Pull Request

To boldly fix the dimensions of the preview image to match the others where many have gone before.

Testing instructions

Create a new account and site at /new and let yourself be swept away by the journey to the editor.

When the NUX modal appears, check that the images are of the same dimension and the jump affect is reduced.

Reported in #41966 (review)

[matticbot]

Test live: https://calypso.live/?branch=update/fse-nux-preview-image-size

[matticbot]

Caution: This PR affects files in the FSE Plugin on WordPress.com
Please ensure your changes work on WordPress.com before merging.

D43989-code has been created so you can easily test it on your sandbox. See this FieldGuide page about developing in the FSE Plugin for more info: PCYsg-ly5-p2

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[ramonjd]

The replacement image for preview.svg looks good and removes the height jump reported in #41966 (review)

When I'm testing however using yarn dev --sync things don't look right at all:

This is both on this PR and a clean master branch (and clean sandbox before sync) 🤷

Usually when I ask the question "Is it just me or...?" I get the answer: "Yes, it's just you."

Hoping to get that answer here as well :)

It should look like (created with a new site + account on Gutenboarding in prod)

[andrewserong]

This is looking good to me after sandboxing D43989-code!

[ramonjd]

Thanks @andrewserong I totally forgot that the build log shows us where to test. TIR (Today I Remembered)