Here's a small, but helpful update.
This week, Facebook has added a new checkbox into its video embed process which enables you to choose a specific time within the video playback at which you want your embed to play from.
As you can see here, there's now a new checkbox option in the embed process which enables you to enter a start time for your playback, so you can choose a specific section that you want the clip to play from, helping to guide people to the most relevant segment, as opposed to simply enabling full playback.
The same functionality has been available on YouTube for a long time, while, theoretically, anyone with some coding knowledge would also have been able to do the same with Facebook video clips (using the "t=[chosen frame start]" operand).
But most people don't have an understanding of coding parameters, nor the time to sort through the specifics on each embed, which makes this a handy option for your process, so you can more easily direct blog readers to key elements or examples within Facebook video clips.