We went to the play session two weeks ago. They just asked the kids to play and they talked to the parents casually one by one. In the end there was a story time and they gave everyone a sticker after that. Then the principal said 'everyone will get an offer' before we left (around 8 kids).
from what I have heard, even if your child doesn't behave well (ex: cry and cannot settle down), they will invite you back for a 2nd chance in another day (not sure if it is true or not).