These pictures were taken "only" 1,000,000 miles away, so the Moon is significantly closer to the camera than Earth was, which makes it appear larger compared to Earth than it really is. The true size comparison is more like [0]. The effect is also more because the

[0] http://qph.is.quoracdn.net/main-qimg-5bff56bc0b31f8b7395bdbe...