[longwave]

It appends another sleep each time you start a new shell, so it subtly slows down over time.

[VHRanger]

wouldn't it do so exponentially?

The first time it does it once, the second time the statement is there twice so it does it twice, then 4, 8, 16, etc. ?

[usrbinbash]

No, because;

    echo sleep 0.01 >> ~/.bashrc

adds this to .bashrc;

    sleep 0.01

It doesn't add itself, so the sleep tie grows linear by 0.01sec each time a shell is opened.

[happyopossum]

No, the entire statement isn't added each time, only the sleep portion.

[Tesl]

the third time the statement is there three times ..