Lucid WordPress theme problem

Hi,

i just installed Lucid (elegantthemes) theme. But i have one problem with this theme, thumnail images act wierd. They should be 150x150px, but instead they are much larger and all my home looks weird because of that.

Also, if anyone knows how to just remove these recent post from this theme, later i just want to use video section instead of recent articles section?

original theme: https://www.elegantthemes.com/demo/?theme=Lucid

my webpage: https://www.purjetamine.com/