Jeff SikesTIL when you upload a video file to Mastodon, it generates a preview thumbnail. The thumbnail isn't passed through to other servers in the ActivityPub payload (similar to preview cards).
Each receiving platform handles this situation differently. Some regenerate a thumbnail (processing again). Some ignore it and don't show one. Others create blank thumbnails to appease the Mastodon API.
A blurhash is passed, tho, and could be used as a placeholder.
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