I can see it, considering the marionette and Security puppet are two different beings ( as marionette looks different and acts differently from security puppet ) plus their music box goes a-bun-aboo bun da da da bum o dun- yeah you get the point.
I can see the two, if possible, being close during closing hours or when ( if Lefty was placed on stage and brought ) no kid is paying attention or he's ( they, He, they go by both every pronoun but mostly He/Him and They/Them ) done performing would he go over to security puppet and watch them. Possibly vibe with the puppet and listen to their music box and chat.
This is possible and I can see it, Security Puppet being a big ol spoon towards Lefty and Lefty being the little spoon. Hah, you thought Lefty would be on top but nope it's the security puppet.
7/10