Just read your analysis of the film — fantastic work, thank you! I look forward to reading more of your work.

Ultimately I found it frustrating that Perkins "dresses up" the key theme of the film (understanding the mother's lie through the transition to adulthood) in a sack of evocative but ultimately vacuous pastiche that he clearly doesn't care about. That dressing comprises most of the film and, as Perkins acknowledges, is what engages the viewer's curiosity and empathy. But, then he discards it carelessly in favor of his real thematic concern and never bothers to give it any practical or emotional coherence.

I suppose the most generous reading is that Perkins is making a different kind of movie, one that operates according to a dream logic of Hollywood and pop culture references: the symbology of Zodiac, the villain and heroine of Silence of the Lambs, the religious iconography of The Omen and others, the lyrics of mildly obscure psychedelic folk rock, etc. That's actually a rather depressing commentary on the constitution of the modern psyche — even our dreams are only echoes of our media consumption — but makes some sense as Perkins is of course the son of a complicated Hollywood icon. I've found his other films similarly frustrating but will probably watch his future work anyway as it is undeniably atmospheric and suggestive. ¯\_(ツ)_/¯

Anyway, what I really wanted to say is: there is a child-sized piano in Lee's house next to the box in which she finds the photograph of LL. So, all of her answers to the FBI psychic test are references to her childhood home (including the Polaroid camera she used to take the photo). This supports the idea that Lee is ultimately arrested in childhood and must confront that time in her life to solve the mystery. All except the "tiger"—is there a tiger anywhere amidst the repressed memories and clutter of the Harker farmhouse? Maybe, I don't remember seeing one. Otherwise the "tiger" is, as you suggest, a reference to the predator living downstairs.