[NRJWallace]

For my mp4 movie files my poster and fanart files are pulled into Kodi and look great  (actor images too).   I am unable to get Kodi so show artwork for the mp4 trailer file.  All I get is an image pulled from an arbitrary position in the trailer with the name of the trailer file underneath.  This looks kinda sloppy.  I would rather one of my artwork files to be displayed but I cant get this to work.   How do I get a nice image for my trailer?  Does it need to be a certain resolution or aspect, does it need to have a certain file name?  I used movie-name-trailer-poster.jpg but that didn't work.

For context, this issue appears when I click on the movie in a library/folder in Kodi and get presented with three things: (1) the back arrow to go back to the list of movies, (2) a poster-like image for the trailer so that when you select it - the trailer plays and (3) a poster of the movie so that when you select it - the movie plays.  Number (3) above is fine, I can see the movie poster.  Number (2) is the issue - all I see is an image pulled from an arbitrary position in the trailer with the name of the trailer file underneath.

Thank you.

[Karellen]

How do I get a nice image for my trailer? 

You can't. There is no provision for trailer artwork. I am not really understanding how and where you are trying to use it.
A trailer belongs to a movie, it's not a standalone library entry. Its like asking how to display a poster for your movie poster.

Maybe you can post a screenshot for clarity on how/where you want to see/use it.