Hi Mladena,

This is a bit difficult because the element does not belong to each slide is displayed separately as fixed element.

if you look into /js/scripts.js you will see in function Portfolio() { ... } the following code that deals with changing active/current slides:

$('.swiper-slide').on('mouseenter touchstart', function() {

      ...

}

for split slider or centered slider and this is where you want to change the image for the external caption.