This means, despite the blockage, there's sufficient light coming through the handkerchief to the solar cell, so that the solar cell is able to decode and stream that information, in this case, a high-definition video.
Ovo znači, usprkos blokadi, dovoljna količina svjetlosti dopire kroz maramicu do solarne ćelije, da bi solarna ćelija dekodirala i  prenijela tu informaciju, u ovom slučaju, video visoke razlučivosti.