textPayload and label.session properties contain "nested" JSON, which is escaped, and these JSON strings sometimes contain further "nested" JSON objects.textPayload as a collapsed node of a tree, at the same level as its peer properties, like insertId, timestamp, and severity, which will cannot be collapsed or expanded. Then anothed collapsed node for labels, and under it another collapsed node for session. textPayload node, it displays that nested JSON object as a normal tree under textPayload. The shape of this nested object is not fixed, so manually deserializing it if a user clicks its + icon is difficult. 