My video post dont have an image

Hi ,

my blog is https://www.thomastansg.org

I just add a video post from youtube.
in my blog page, before that post which i just made, is there any way i can have a logo or the video image there?

Now it has nothing, just the title.
And also notice my middle column, its say pending thumb…
Well, it is very ugly to have such a presentation.

Anyways i can improve that?

Please advise with lots of thanks!