What does this mean?

Question

W

Wh

Wha

What

What?

C

Co

Coo

Cool

H

Hm

Hmm

Hmmm

Answer 1

W

Wh

Wha

What

What?

C

Co

Coo

Cool

H

Hm

Hmm

Hmmm

This means that someone was texting in response to something that you said. That person was trying to be clever by adding one letter to complete a word. The text was "What? Cool. Hmmm." So whatever you sent to this person who was asleep or not really awake mentally, that person liked your idea.