old_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class UserProfile(models.Model):
    user = models.OneToOneField(User)
    description = models.TextField(max_length=3000)
    picture = models.ImageField(upload_to='media/profiles/')
    thumbnail = models.ImageField(
      upload_to='media/profiles/thumb/',
      max_length=500,
      null=True,
      blank=True
    )
    follows = models.ManyToManyField("self", blank=True)
  
  
  
new_contents: from django.db import models
  from django.contrib.auth.models import User
  
  
  class UserProfile(models.Model):
    user = models.OneToOneField(User)
    description = models.TextField(max_length=3000)
    picture = models.ImageField(blank=True, upload_to='media/profiles/')
    thumbnail = models.ImageField(
      upload_to='media/profiles/thumb/',
      max_length=500,
      null=True,
      blank=True
    )
    follows = models.ManyToManyField("self", blank=True)
  
  
  
subject: Change user_profile so picture can be null