My sil does this, we live far enough apart that it doesn’t make a huge difference, but it is everything from lights to pergola to patio, to rugs. She also copies my clothes, so if I turn up wearing x and we are going out she gets changed into something that’s as close to it as possible,
but I’ve noticed she also copies other people, their cars and holidays, she’s went on the same holiday as us numerous times, it appears she sees something she likes someone else has or wears or does and then she does it.
i put it down to she simply lacks the ability to come up with ideas herself, i don’t find it annoying, i find it uncomfortable, i feel an element of discomfort when we visit snd i see the next identical thing, but i dislike intently when she tries to dress like me but as she’s small and obese and im tall and a health weight, its limited to things like i wear a green jumper and black jeans and she puts on a green jumper and black jeans. If I wear something like a midi skirt, she will exclaim oh I can’t wear stuff like that as I’m short, whilst eyeing me up and down, I just nod and change the subject.
as we are in our fifties I do find it really uncomfortable, I saw her recently do it to some friends, where one got a new car and she went on and on about getting one to her husband, and then another talked about their holiday and she’s now decided to book it,
I know it’s a sign of flattery, it means she thinks whatever it is is good, but it is uncomfortable when it’s constant.