This is called Title Swapping trick. It is used to swap the old Blogger Title to New Blogger title. Swapping Title Boost your position in search engines (Google) and also increase click-through. From an SEO viewpoint page title is the most important element of your blog. When you look your browser title bar you notice that your blogger default Template display your blog title in front of each post title. Like this
After Swapping the Blog title. Its look like this.
How to optimize blogger post titles
Step 1. Log in to your Blogger Dashboard > Template > Edit HTML
Step 2. Find ( CTRL + F ) this code
Step 4. Replace the above code with this below code
<b:if cond='data:blog.pageType == "item"'>
Step 5. Now Save the Template you are done