The Universalis downloads and apps have blue arrow buttons inside them which let you choose different options each day. See, for example, How the Selection Switches Work for Mass. (The web site does the same kind of selection in some cases, but it does it using ordinary links).

If you print out a page from Universalis and you end up with blue arrows on the paper, tapping or clicking those buttons does nothing. The paper does not change.

An e-book is just paper inside an electronic box. Tapping or clicking arrows in it would do nothing. Consequently e-books created using Universalis do not show the arrows at all. This applies both to Kindle e-books and to e-books in the ePub format.

The selection switches for Mass let you choose which readings you want to use for Mass that day. For instance, on a memorial, you may want to ignore the General Instruction of the Roman Missal’s instructions (at §357) and use the readings for the memorial rather than the readings for the ferial day.

When you use the Universalis program on your computer to create an e-book, the program uses whatever selections you have chosen within the program. If you chose the readings for the memorial on a particular day, those are the readings which will appear in the e-book. So if you have particular preferences for readings on memorials (and also for optional memorials), go through the calendar in the program and set the selections accordingly. Then all future e-books that you make will respect your selections.

Kindle Fire

In order to confuse their customers, Amazon use the same name for their e-book readers (the Kindle) and their tablets (the Kindle Fire). In fact the Kindle Fire (modern versions) and the Kindle Fire HD are not Kindles but programmable devices, and you can buy the Universalis app for them, blue buttons and all.