I agree with you, this demand for a city shopping mall should be sufficiently satisfied by Emonika I guess. Although I am not sure about the timeline and urbanistic qualities, I know this project only from some renders available online, when I studied in LJ.How this makes sense if the majority of people in Ljubljana goes shopping for clothes or go to the cinema in BTC instead of going to the city centre. We have mainly full streets because of tourist and because locals are going very often to the bars at the river banks. We are not talking about 4 shopping malls like in Bratislava but only one who will bring more people to the city center. I agree with you that we don't need so many shopping malls like Bratislava but we definitely don't need new shopping boxes like this one who is building in Šiška. City parts like Šiška need new housing buildings where ground floors have content like shops instead of building ugly shopping boxes.
Regarding Šiška, big box concepts are definitely not an optimal solution for urban areas, particularly along major roads such as Celovška. However I think that BTC is a bigger urbanistic problem for LJ than Spar Šiška.