Hi Paul,
In case of multiple photos you want to post and to get thumbnail look this is the procedure, after you have uploaded the photos.
Step one
Select the desired photos, and then click generate html and img code, as shown on photo 1
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Photo Linking and Thumbnails?
Step two, select third option on the screen
IMG clickable thumbnails for message boards - recommended and then copy it to desired post
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Photo Linking and Thumbnails?
If you have done everything right you should get this as result

Photo Linking and Thumbnails?

Photo Linking and Thumbnails?
Just in case I have uploaded the photos on LLL as well