The banner on our demo is a slider and added using shortcode
[rev_slider alias=”shop-banner”], if you want to show this banner for a category go to Products > Categories > edit the category and add slider shortcode in the category description http://prntscr.com/hzc9qm.
Also, if you want to add just banner without any effects when text appears you may use simple image. If you want to add appearing effects etc you may use Revolution slider and use Hero Scene type https://www.themepunch.com/revslider-doc/slider-setup/#slidertype.
Feel free to ask if you have any other questions.