No.
OK, let’s try this:
Is it expected that people changing a baby would touch the doll in any way?
Is it expected that they would move it to a different position, in the course of what they’re doing?
Is it expected that they would merely look at the doll?
Is it expected that they would just ignore it?
Is it expected that a person using the restroom for any purpose other than changing a baby’s diaper would interact with the doll in any way?
Are there some other non-diaper-changing circumstances in which it would be expected that a person using the restroom would interact with the doll?
reply to Chronos:
OK, let’s try this:
Is it expected that people changing a baby would touch the doll in any way? No.
Is it expected that they would move it to a different position, in the course of what they’re doing? No.
Is it expected that they would merely look at the doll? Yes.
Is it expected that they would just ignore it? No.
Is it expected that a person using the restroom for any purpose other than changing a baby’s diaper would interact with the doll in any way? No.
Are there some other non-diaper-changing circumstances in which it would be expected that a person using the restroom would interact with the doll?
No.
Is the doll visibly wearing a diaper?
If so, is the diaper visibly of a specific brand?
replt to thorny_locust:
Is the doll visibly wearing a diaper? No.
If so, is the diaper visibly of a specific brand?
N/A.
Just to be certain: We’ve already gotten a no answer to “does the doll act as a sign,” but is there some other sense in which it is meant to convey information?
reply to dirtball:
Just to be certain: We’ve already gotten a no answer to “does the doll act as a sign,” but is there some other sense in which it is meant to convey information?
Not a sign. Not meant to convey information.
You said it was probably a kid who did this. Had they misunderstood an instruction printed on the changing table?
Would the purpose of hanging the doll there likely be apparent to any random person who might happen to walk in?
If not, would the purpose become apparent when someone used the changing station?
Is there a known purpose to the doll’s having been hung there? Or is it just hanging there and you don’t know why?
No.
reply to dirtball:
Would the purpose of hanging the doll there likely be apparent to any random person who might happen to walk in? Yes.
If not, would the purpose become apparent when someone used the changing station?
Not necessary to use station. 
I am pretty sure I know why.
Could a non-doll-object have served the same purpose? A small cloth pillow? A rubber ball? A yarn pom-pom? A piece of paper?
reply to Chronos:
Could a non-doll-object have served the same purpose? A small cloth pillow? A rubber ball? A yarn pom-pom? A piece of paper?
I think an infant doll of any type works, but nothing else I can imagine. Certainly none of the items you list would work.
Does the doll serve simply to identify it as an infant changing station (if, for some reason, that’s not otherwise obvious)?
Is the doll there to illustrate that if the caretaker isn’t careful the infant might fall off the table while tangled in the restraining straps and wind up hanging in the same fashion as the doll?
No.
No.
Was the doll left accidentally by a previous diaper changer, and was put there
so that they might retrieve it at their next visit ?