This version that I received is just a photocopy of all the pages of the original book. It even has the owners' underlines and other markings, how annoying.
You can not activate anything to make the print bigger unless you are reading from a screen that allows enlargement by zooming in and out. Otherwise, what you see is what you get. That's about the best that you will get.
For me, it is an eye strain. I am under the impression that whoever uploaded this version was too lazy to retype the book and found it easier to just copy it to make a dollar per sale.
I suppose this is the reason why it only cost me .99 cents plus tax while other, more suitable versions, are above $10. They put in the work to make it Kindle friendly and to meet Kindle's standard.