.....And
frozen in time.Many fans in the Utena world feel that Juri is in love with Shiori during the series. Although I will not dispute this, I am just offering an alternate view.
Juri doesn't love Shiori during the series. In fact, she hates her, an emotion she states several times. The Shiori Juri loves is the Shiori she knew before the boy-stealing incident. She loves the innocent, younger Shiori, the Shiori before she hurt her.
She holds onto the picture, the moment frozen in time. When Shiori got it into her head to "steal" the boy she thought Juri liked, the Shiori Juri loved was lost. The school picture captures that moment, Shiori turning from her innocence. Juri remembers this as that turning point, when the girl she loved died and she hated the new incarnation.
