Upfront caveat: These could be Photoshopped fakes. Ad agencies do it all the time to try to win awards. But the agency here is part of the third largest ad network in the world, so the campaign is more likely to be legit.
From the agency press note:
The USB market in India is dominated by global players like Transcend and SanDisk. What distinguished our product from these leading players was our superior storage capacity. Hence, we were asked (by BrandSTIK) to think of a low-budget idea to capitalise on this differentiating factor and try to make a mark in this highly competitive market.
Idea: We made massive USB connectors and ﬁxed them on the rooftops of multiplexes and buildings, making the entire structures appear like giant USB ﬂash drives.
The agency, Publicis in Mumbai did enter this idea in Spikes Asia, the continent’s largest ad festival. So, they exposed it to vetting, which makes me think it’s more likely to be real.