https://player.vimeo.com/video/284953008

This film shows the behaviour of three autistic children during a birthday party.  Each child behaves in a different way,  however each of them struggles with difficulties in the same area:

S: social interactions

I: imagination

G: gestures

N: non verbal communication

S: sensory responses

These form the signs of autism. These signs have to be taken as a cluster (i.e., a difficulty in only one or two of these areas cannot be taken as a sign of autism).

https://www.asdinfowales.co.uk/autismchildsigns