You can create for yourself a contact entry within the Contacts app in Android Lollipop. This is useful, for example if you want to send a business card from wirelessly to a contact. The "Me" contact will appear in the List of the Contacts app at the top and can of course also be provided with a profile picture or contact picture.
If you have specified a contact picture for yourself by fun and now want to undo it then you can use the following procedure in Android Lollipop:
Open the Contacts app and tap in the section "ME" on your name. You will now see your contact details. Tap the pencil icon at the top right and you can now edit the contact. In Edit mode now tap the profile image which is displayed in a circular shape. A small pop-up menu will now open where you can select "Remove". Finished!
You just successfully deleted the contact picture for your own contact in Android lollipop.