See your link the way LinkedIn does
Every time someone pastes your link, a crawler reads your page and draws a card. Most designers never look at what it reads.
You can see it yourself with one command:
curl -sA "facebookexternalhit/1.1" https://your.site/page | grep -oE '<meta property="og:[^>]*>'If a tag is missing here, it is missing in the post. The card is built from the tags in your HTML, defined by the Open Graph protocol.

LinkedIn’s own guidance asks for an image of at least 1,200 by 627 pixels, a 1.91 to 1 ratio, in its help article on shareable pages.
Fixed it and the old card still shows? LinkedIn says to allow 48 hours. Or paste the link into Post Inspector to fetch it again right away.
My site draws a card for every page from its own type at build time, and the build fails if a page is missing one.
Your link is the first screen most people ever see.
Want it as slides? Download the carousel.