what a waste

[user_gary]

They turned the pages, which were yellow and crinkly, and it was awfully funny to read words that stood still instead of moving the way they were supposed to -- on a screen, you know. And then, when they turned back to the page before, it had the same words on it that it had when they read it the first time.

`Gee,' said Tommy, `what a waste. When you're through with the book, you just throw it away, I guess. Our television screen must have had a million books on it and it's good for plenty more. I wouldn't throw it away.'

Please explain the highlighted group of words.

I guess, `the television screen' refers to `computer monitor screen'

and the highlighted `it' refers to (computer monitor screen).

Please help me.

[Tdol]

It's a waste because words on paper cannot change, while a screen can display endless texts. The TV screen could be used as a monitor.