Minimal example which shows that traversing ref attributes from an entity result in just the keyword for entities with :db/ident and in the full entity for entities without a :db/ident.

entity.clj

(require '[datomic.api :as d])

(d/create-database "datomic:mem://test")
(def conn (d/connect "datomic:mem://test"))

;; Add the schema
(d/transact conn [{:db/id (d/tempid :db.part/db )
                   :db/ident :community/type
                   :db/valueType :db.type/ref
                   :db/cardinality :db.cardinality/one
                   :db/doc "A community type enum value"
                   :db.install/_attribute :db.part/db}
                  {:db/id (d/tempid :db.part/db )
                   :db/ident :community/neighborhood
                   :db/valueType :db.type/ref
                   :db/cardinality :db.cardinality/one
                   :db/doc "A community's neighborhood"
                   :db.install/_attribute :db.part/db}
                  {:db/id (d/tempid :db.part/db )
                   :db/ident :neighborhood/name
                   :db/valueType :db.type/string
                   :db/cardinality :db.cardinality/one
                   :db/unique :db.unique/identity
                   :db/doc "A unique neighborhood name (upsertable)"
                   :db.install/_attribute :db.part/db}])

;; Add one enum constant
(d/transact conn [[:db/add (d/tempid :db.part/user )
                   :db/ident :community.type/twitter ]])

;; Add one community with type and neighborhood
(let [neighborhood-id (d/tempid :db.part/user )]
  (d/transact conn [{:db/id neighborhood-id
                     :neighborhood/name "foo"}
                    {:db/id (d/tempid :db.part/user )
                     :community/type :community.type/twitter
                     :community/neighborhood neighborhood-id}]))

(def db (d/db conn))

(def community (->> (d/q '[:find ?e :where [?e :community/type]] db)
                 ffirst
                 (d/entity db)))

(:community/type community)

(:community/neighborhood community)