LinkedIn reads Open Graph meta tags for the title, description, url, and image, but it prefers oEmbed data if available. If your site offers oEmbed link tags, as WordPress does by default, then LinkedIn will prefer the oEmbed data values over the Open Graph meta tag values.
If you use a plugin to create Open Graph meta tags, make sure that plugin also offers accurate oEmbed data for your webpage — for example, the WPSSO Core plugin updates the default WordPress oEmbed data with any custom Open Graph values you may have entered (ie. a custom image, title, description, etc.).
The first time that LinkedIn’s crawler visits a webpage, it will cache the meta tag and/or oEmbed values for approximately 7 days. If you later update the webpage’s description, select a new image, fix a typo in the title, etc., you will not see that change reflected on LinkedIn for past or future shares of the same URL until LinkedIn’s cache has expired (approximately every 7 days).