Dog loves being picked up but growls when she is put back down?

I have searched this behavior online and never found anything that describes what I'm talking about or answers the question of why it's done. My dog is an 8 year old fixed female yorkie poodle mix in great health besides a little bit of arthritis in her feet, she's built quite sturdy but gets along really well (still runs, jumps, and plays comfortably).

My dog likes being held and picked up and is a super even-tempered, non-aggressive creature. she almost always asks to be picked up by lightly tapping on your leg and then holding an arm out, then gives a little hop to "help" pick her up. sometimes she's VERY insistent on being picked up.) For some reason, when my partner or friends or anyone besides me goes to put her back on the ground after holding her, she will turn around and growl or snap at them directly after her feet are on the ground. It's only a split second so we don't know if she's playing (she's never actually bitten or hurt anyone) or if she's upset about something.

I've seen many posts about dogs growling when being picked up, but never one about them growling while being placed back on the ground. We are confused by this behavior and don't know whether to be stern and discipline it or if she's playing around, as she is very playful. She's not an overtly vocal dog, so this is something we always notice. It started when she was maybe around three years old(give or take)? Any ideas as to why a dog would react that way?