That is the 'shop' that acts as entry to the Papiliorama.
Visitors buy tickets to enter the park/exhibit here.
I actually wonder if it should be mapped separately, since (from survey there) I know that there's no other way to enter the Papiliorama than through the turnstile there.
There's also a 'souvenir' shop there, shich can be visited without paying the entry fee to the park.