Christian-Wicca is an alleged "tradition" of Wicca that blends the religions of Christianity and Wicca. Followers of this alleged tradition will use Wicca as a base or foundation and then add Christian elements to the mixture, such as veneration of Jesus, the Holy Spirit, the Virgin Mary and the Saints. Imagery such as the Christian cross is also "borrowed" and usually incorporated into the Wiccan pentacle. Christian teachings such as Satan, original sin, and hell are genuinely rejected by believers.
The reality of course is that there is no such thing as "Christian-Wicca". Neither Christianity nor Wicca allows blended or dual faiths. You can be a Christian or a Wiccan, but you cannot be both per the rules of both religions.
Many people who claim to be part of this "tradition" suffer from the belief that Wicca is an "anything goes" religion where one can do whatever one wishes and still be free to slap a Wiccan label on it.
In a nutshell, people who claim to practice "Christian-Wicca" are neither Christian, nor Wiccan and are simply practicing their own self-made spirituality and then simply pretending as if is a valid tradition.