Learning that she can initiate contact (or "hand an object to someone") and get something in return (in this case, interaction) is a precursor to other forms of communication. It's a step that DD is still working on. As difficult as it may be for those not in our situation to understand, this is her level of communication right now. She's been content to let us do the communicating for her. Now she's beginning to want to initiate contact/get a response from someone herself, and we want to encourage that.
She can't read. This is a precursor to her using the PECS system (Picture Exchange Communication System), where she can use cards with symbols on them to indicate what she wants. She doesn't know what the symbols in PECS mean right away either. She learns by our verbal reinforcement (for example, showing a picture for "more" or "open", if she chooses open we verbally say "oh, you want us to open this (whatever it is)?"...as she gets the reinforcement and follow on action, she learns what the symbol means (the card also has the word on it for when she starts reading). We will reinforce what is on our card with her while we are at Disney as well.
For Halloween she used this PECS card to "say" trick or treat at each house. She gave the card while I indicated that this was her saying "trick or treat", and she got a verbal response from neighbors as well as candy.
What you are referring to is much like PECS, which is also the same type of cards that will be on her AAC device. She does not yet have the vocabulary in this system to be able to use it at Disney as you are suggesting. We have 5 words that we are working on in this system at the moment, and they are not ones that would be particularly helpful in a M&G situation. (Nor does she have an AAC device to be able to take to and from school at this point. We are in the middle of that process right now).
We have discussed this at length with her SLP, and her SLP agrees that this step could be very reinforcing for her at Disney. I understand that it may not seem like communicating to others, but it is a big step for her and one we want to encourage as best we can.