The propaganda works to effect people's perspectives because it changes their view on Hitler. It emphasizes on the image of him being a good, reliable leader and a happy person who's best interest is out to the children. It doesn't allow them to see the bad side of him. The image itself effectively changed people's perspectives because it led to people portraying him as a 'god like figure' or messianic.
In my opinion, this exact image is being recreated with our presidents, leaders, etc. To be good with kids is a very important trait when running something big because people then view them as kid-friendly and an excellent candidate. Hitler knew that and used it to his advantage. If someone were to stumble upon this picture today, having no previous knowledge of Hitler or the Holocaust they too would most likely believe of him to be a good and trusting leader. There is always a different side to a person that is never shown publicly.