In Blade Runner 2049, Dr. Stelline implants one of her own memories into K's. This memory concerns a wooden horse on which is written an important date, and K is able to use this memory to locate it at an orphanage decades later. He is able to trace it back to Las Vegas thanks to a telltale radiation signature. I have two questions regarding this horse:
a) My understanding is that Deckard left for Vegas before Stelline was born. If he did, how did she end up with the horse which had apparently been made, or at least spent time in, Vegas?
b) Why exactly did Stelline implant the memory of the horse? Presumably this was done deliberately, as it would potentially allow a replicant to locate Deckard. Did she simply hope someone would be able to bring him to her? Wouldn't that risk (indeed, perhaps probably guarantee) exposing her identity to Wallace? Also, K only becomes interested in finding the horse when he sees the same date at Sapper's farm, through an apparent coincidence. Was there more going on there?