JSON Schema uses 'image' for a Person and 'logo' for an Organization.

layouts/partials/templates/schema_json.html

@@ -6,7 +6,11 @@
   "name": {{ site.Title }},
   "url": {{ site.Home.Permalink }},
   "description": {{ site.Params.description | plainify | truncate 180 | safeHTML }},
+  {{- if (eq site.Params.schema.publisherType "Person") }}
+  "image": {{ site.Params.assets.favicon | default "favicon.ico" | absURL }},
+  {{- else }}
   "logo": {{ site.Params.assets.favicon | default "favicon.ico" | absURL }},
+  {{- end }}
   "sameAs": [
     {{- if site.Params.schema.sameAs }}
       {{ range $i, $e := site.Params.schema.sameAs }}{{ if $i }}, {{ end }}{{ trim $e " " }}{{ end }}