I think in the Rails mailer context you're expecting "render a view" to be a comfort zone for the reader, the line is suggesting a mental model you hopefully already have that will really help you understand how the upcoming process will work. "It's kind of like view rendering, so I should expect a template file and the need to correctly set header fields."

I learn best by analogy, so the first version in the article was very helpful and comforting. The second version makes me, and I think the parent and grandparent, expect that view rendering is more like requisite knowledge than a possibly useful analogy. "Only true experts in how views are rendered need apply, I better study that first."