How (or why) does this bash script snippet work?

[Dean S. Messing]

On Fri, 13 January 2012 at 15:37, Cameron Simpson wrote:
> On 12Jan2012 19:07, Dean S. Messing <deanm at sharplabs.com> wrote:
> | On 13 Jan 2012 at 13:55:27, Cameron Simpson wrote:
> | <snip>
> | > The:
> | > 
> | >   <foo command [args...]
> | > 
> | > form is handy for programmatically constructed pipelines, too.
> | 
> | Sorry, I don't understand "programmatically constructed pipelines".
> | Would you elaborate?  Thanks
> 
> Where one has a script that figures out a pipeline and assembles it.
> So one might have a file conversion tool that goes:
> 
>   my-convert-script src-file dst-file change1 change2 change3 ...
<snip>

I see.  Elegant. Thanks!