Why is there a "bash" and "" on the solution of exercise 4 of the "Streams" Lab 2, of the Advanced Bash Scripting Course?

Shell Scripting
#1

I don’t think there was any mention of the need to use either previously in the course, so I fail to see the logical need for it in the solution (specially considering the command fails to execute as expected without both of them).

#2

Your title doesn’t make sense, Bash and what?