I wandered at what the presence of the shine meant myself when it was shown back in its respective episode. I read an opinion that stated the presence of the shrine and the warding talismans that surrounded it and its proximity with Yuuko's body was the big reason Kirie concluded that Yuuko was not an evil spirit - because one such being wouldn't survive(?) or stay there without ill effects.

Is it common for (or even the definition of) a shrine in Japan to contain some sealed entity? I know they're a place of worship.. but not sure if they had to trap (or at least be the residence of) the respective spirit.