Hello There,
Thanks for writing in!
I can see that you are using Ethos stack.
1.) The masonry layout does not have an excerpt. Adding an excerpt may destroy the masonry layout. It may lead to unordered post items and will no longer align each of the post items. This is also considered a custom modification for the Ethos Blog layout because it requires recoding of the masonry layout and the styling for the outcome of the masonry blog layout.
2.) If you keep in a standard view, you already have that effect. You just need to insert more post items and make sure that it has a featured image. You can check out the Ethos 1 demo here: http://demo.theme.co/ethos-1/
if in case, it is not displaying all the post items, you might have enabled the “Filterable Index” option. You can disable this option in X > Theme Options > Ethos > Blog Option. Enabling the filterable index will bypass the standard output of your blog page, allowing you to specify categories to highlight. Upon selecting this option, a text input will appear to enter in the IDs of the categories you would like to showcase.
Hope this helps.