Thanks a lot. I used your Moon photos to crop the black background and make the background transparent (thus become .png files) so that it will appear on HA more realistic
- platform: template
sensors:
moon_phases:
entity_id: sensor.moon
friendly_name: 'Moon'
value_template: '{{ states.sensor.moon.state }}'
entity_picture_template: /local/moon_phases/{{ states.sensor.moon.state }}.png