Django　backgroundシグナル下のrequest.postの役割について

djangoでチャットアプリを作りたいと考えています。そこで参考になるコードを探していたところ気になるコードを見つけたので、質問させていただきます。
該当のdjangoプロジェクトのコード
このプロジェクトの中の/api/chat/task.pyと/api/chat/signals.pyに気になるコードがあります。以下の通りです。

urls.py

"""api URL Configuration
The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/2.1/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.urls import include, path
    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.contrib import admin
from django.urls import path, include, re_path

urlpatterns = [
    path('admin/', admin.site.urls),
    re_path(r'(?P<version>(v1|v2))/', include('api.chat.urls'))
]

/chat/url.py

from django.urls import path, include
from rest_framework.routers import DefaultRouter
from rest_framework_extensions.routers import NestedRouterMixin
from rest_framework_simplejwt import views as jwt_views

from api.chat import views


class NestedDefaultRouter(NestedRouterMixin, DefaultRouter):
    pass


router = NestedDefaultRouter()
rooms_router = router.register('rooms', views.RoomViewSet)
rooms_router.register(
    'messages',
    views.MessageViewSet,
    base_name='room-messages',
    parents_query_lookups=['room']
)


urlpatterns = [
    path('', include(router.urls)),
    path('users/', views.CreateUserView.as_view()),
    path('users/<int:pk>/', views.DetailUserView.as_view()),
    path('auth/login', jwt_views.TokenObtainPairView.as_view()),
    path('auth/refresh', jwt_views.TokenRefreshView.as_view()),
]

models.py

from django.contrib.auth.models import User
from django.db import models


class Room(models.Model):
    title = models.CharField(max_length=100, blank=True, default='')
    participants = models.ManyToManyField(User)

    def __str__(self):
        return self.title


class Message(models.Model):
    created_at = models.DateTimeField(auto_now=True)
    sender = models.ForeignKey(User, on_delete=models.CASCADE)
    room = models.ForeignKey(Room, on_delete=models.CASCADE)
    content = models.TextField(blank=True)

    def __str__(self):
        return self.content

views.py

from django.contrib.auth.models import User
from django.http import Http404
from rest_framework import generics, permissions, viewsets
from rest_framework_extensions.mixins import NestedViewSetMixin

from api.chat import models, serializers


class CreateUserView(generics.CreateAPIView):
    permission_classes = (permissions.AllowAny, )
    queryset = User.objects.all()
    serializer_class = serializers.UserSerializer


class DetailUserView(generics.RetrieveUpdateDestroyAPIView):
    queryset = User.objects.all()
    serializer_class = serializers.UserSerializer

    def get_queryset(self):
        user = self.request.user
        return User.objects.filter(id=user.id)


class RoomViewSet(NestedViewSetMixin, viewsets.ModelViewSet):
    queryset = models.Room.objects.all()
    serializer_class = serializers.RoomSerializer

    def get_queryset(self):
        user = self.request.user
        return user.room_set.all()


class MessageViewSet(NestedViewSetMixin, viewsets.ModelViewSet):
    queryset = models.Message.objects.all()
    serializer_class = serializers.MessageSerializer

    def get_queryset(self):
        parents_query_dict = self.get_parents_query_dict()
        room_id = parents_query_dict.get('room')
        user = self.request.user
        if not user.room_set.filter(id=room_id):
            raise Http404

        queryset = super().get_queryset()
        query = self.request.GET.get('q')
        if query and self.action == 'list':
            queryset = queryset.filter(content__icontains=query)
        return queryset

task.py

from datetime import timedelta

import requests
from background_task import background
from django.utils import timezone

from api.chat.models import Message


@background
def push(to, content):
    data = {
        'device_id': to,
        'content': content,
    }
    try:
        requests.post('localhost:7000', json=data)
    except requests.exceptions.InvalidSchema:
        pass


@background
def msg_remover(lifetime):
    deadline = timezone.now() - timedelta(seconds=lifetime)
    Message.objects.filter(created_at__lt=deadline).delete()

signals.py

from django.conf import settings
from django.db.models.signals import post_save, post_migrate
from django.dispatch import receiver
from django.utils import timezone

from api.chat.models import Message
from api.chat.tasks import push, msg_remover


@receiver(post_save, sender=Message)
def push_notification(sender, instance, **kwargs):
    msg = instance
    rest = msg.room.participants.exclude(id=msg.sender.id).all()
    for person in rest:
        push(to=person.id, content=msg.content)


@receiver(post_migrate)
def start_tasks(sender, **kwargs):
    lifetime = settings.MSG_LIFETIME
    msg_remover(
        lifetime,
        repeat=lifetime / 10,
        schedule=dict(
            run_at=timezone.now(),
            action=1,
        ),
    )

task.pyのpushでは、一体何を行っているのでしょうか。
signals.pyのpush_notificationからの流れで考えると、Messageインスタンスが保存されると、メッセージを送った人以外のチャットルームにいる人をdevice_idに格納してlocalhostにPOSTリクエストを送っているように思われます。
しかし、localhostにPOSTリクエストを送った後、一体どのような処理が行われるのでしょうか。
ご教示お願いいたします。