If you don't have an image in your profile, it shows up blank.
Although you might prefer anonymity, it would enhance your students' experience if you added a personal image.
First, get your picture:
You might want to use a photograph. Unless you have a square image, you will need to crop the
photo. Here's how you can edit the photo, ready for your profile :
Then add the picture to your profile in Moodle as follows:
To access your profile, click your name (at the top)
Then on the left, under Settings, click Edit profile
Scroll to User Picture, add your image (JPG or PNG) then