LinkedIn may be showing a cached preview. Seeing the new image in your own browser does not establish that LinkedIn fetched it again. Use Post Inspector to check the preview for a new share. 1
Verify the page first
Inspect the public URL’s HTML for og:title, og:description and og:image. The image should point to the intended publicly accessible file. These Open Graph properties describe the page’s preview information. 2
If an image’s contents changed while its URL stayed the same, check the image cache as well. A new filename for the new artwork, followed by an updated og:image, can make asset versioning clearer. You do not need to change the article URL.
Then inspect the shared URL
Enter the URL in LinkedIn’s Post Inspector and check the retrieved title and image. If they are wrong, fix the page metadata or access before publishing the share.
There is an important limitation: LinkedIn’s guidance says the refresh affects new posts using that URL. An existing post’s preview can remain unchanged. 1
Avoid creating endless random query-string variants as a substitute for fixing the underlying response. Keep a clear article address, and diagnose the website’s image delivery separately from the social platform’s cached preview.
Related reading
Website implementation and improvements