Messaging SDK | iOS | setting and clearing custom fields

Can you please help in explain what is meant by "client side context change "
What i have tried from my end

1. Added few custom fields in the new conversation 
2. Tried updating the fields - by adding new fields in the ongoing conversation - Not able to see the new fields in the zendesk portal.
3. Tried clearing the fields and than passing the updated fields  - Still the old fields are seen in the zendesk portal.

[Zendesk.instance.messaging setConversationFields:@{@"4422761977114": @"FA2590"}];

[Zendesk.instance.messaging clearConversationFields];