Please Explain This “Electronic Signature” Oddity

Below is the signature page from a Courtyard Marriott group sales agreement I found online. I know next to nothing about electronic signatures, but I found decidedly odd the e-signature process specified in this contract. “Replace Empty Box with Blackened Box Here to Enter Into Binding Obligation”? And check out the note at the bottom about how you can do it using Word.

Can anyone explain this to me and where it fits in electronic-signature doctrine?

About the author

Ken Adams is the leading authority on how to say clearly whatever you want to say in a contract. He’s author of A Manual of Style for Contract Drafting, and he offers online and in-person training around the world. He’s also chief content officer of LegalSifter, Inc., a company that combines artificial intelligence and expertise to assist with review of contracts.