If it responds "Validating", the node is validating the given chain. If it responds "Syncing", then the chain tracked by this node but it is not validating. If it responde "Created" then the chain exists but it is not being synced. Note that in order to validate or watch a subnet, you need to start your node with argument --whitelisted-subnets=[subnet ID goes here] (e.g. --whitelisted-subnets=KL1e8io1Zi2kr8cTXxvi321pAzfQuUa8tmBfadqpf9K2dc2TT) as well as add the node to the subnet's validator set.