What is the difference between a join of two tables and a join with a subquery?

Question

PostgreSQL

There are two requests:

Original request:

SELECT *
FROM main_thinghistory
JOIN (
    SELECT main_thingownershiphistory.thing_id AS thing_id,
           date(main_thingownershiphistory.date_start) AS dt
    FROM main_thingownershiphistory
    JOIN main_thing
      ON main_thing.id = main_thingownershiphistory.thing_id
     AND main_thing.status IN (9, 4, 5)
     AND main_thingownershiphistory.is_deleted = false
     AND main_thingownershiphistory.date_start < 2020-06-02 00:00:00
     AND main_thingownershiphistory.old_owner_id IS NOT NULL
    JOIN main_legalperson
      ON main_legalperson.id = main_thingownershiphistory.owner_id
     AND main_legalperson.is_service_company = true
    WHERE main_thing.office_id != 210
    ) AS anon_1
ON main_thinghistory.thing_id = anon_1.thing_id
   AND main_thinghistory.history_date = anon_1.dt
   AND main_thinghistory.history_date >= 2012-01-01
   AND main_thinghistory.history_date <= 2020-06-01
   AND main_thinghistory.is_deleted = false

Rewritten query:

SELECT *
FROM main_thingownershiphistory
INNER JOIN main_thing
   ON (main_thingownershiphistory.thing_id = main_thing.id)
INNER JOIN main_legalperson ON (main_thingownershiphistory.owner_id = main_legalperson.id)
INNER JOIN main_thinghistory ON (main_thing.id = main_thinghistory.thing_id)
WHERE NOT (main_thingownershiphistory.is_deleted = True)
  AND main_thing.status IN (9, 4, 5)
  AND main_thingownershiphistory.date_start < 2020-06-02 00:00:00
  AND main_legalperson.is_service_company = True
  AND NOT main_thingownershiphistory.old_owner_id IS NULL
  AND NOT main_thing.office_id = 210
  AND main_thinghistory.history_date = main_thingownershiphistory.date_start
  AND main_thinghistory.history_date >= 2012-01-01
  AND main_thinghistory.history_date <= 2020-06-01
  AND main_thinghistory.is_deleted = False

The question is why these queries are not equivalent?