Bushwick displays the first, most recent, post in its entirety. For all posts after the most recent post, it displays only the post title.
If instead you'd like all posts to display just an excerpt, you can follow these instructions that I gave someone else:
In addition to following that guide, you'll need to make one more change in your child theme to display excerpts instead of full posts.
Make a copy of content.php and place it in your child theme. On line 17 of this file in your child theme, change this:
the_content( __( 'Continue reading <span class="meta-nav">→</span>', 'bushwick' ) );
the_excerpt( __( 'Continue reading <span class="meta-nav">→</span>', 'bushwick' ) );
That should do the trick. I just tested the changes in a child theme on a test site on my end and it's working.
Here's the Codex reference about the_excerpt in case you'd like to read up on it:
Let me know how it goes!