Here, just = really, great deal, truly, etc....It's an intensifier, and it is frequently used with verbs that express preference or favorability (love, adore, etc).
I just love the pizza at this restaurant!
I just adore the view from our hotel room!
Interestingly, "just" is often used as a synonym for "only" and another synonym for only (simply) can be used in similar fashion:
I simply love the pizza at this restaurant.
I simply adore the view from our hotel room.