Help Me Understand: Chapter 7 to_self_delay description

[shaurya947]

Which topic needs more explanation?
Description states:

A very important security parameter for the protocol. The value in the open_channel message is used in the responder's commitment transaction, and the accept_channel in the initiator's. This asymmetry exists to allow each side ...

I understand that to_self_delay is returned back in the accept_channel message. What does the above description mean by "...and the accept_channel in the initiator's"? Is it an incomplete sentence?

Also what "asymmetry" is being referred to? The asymmetry in the commitment transactions held on to by both parties? This should be clarified perhaps?