Worship of "graven images" and Deity worship
All scriptures are from Krishna, but not all scriptures are equal, just as there are math books for both second grade math students and there are textbooks for those studying calculus. All are correct, but one is for those with higher understanding.
Deity seva requires deep understanding. Worship is not casual or arbitrary, nor is it meant to present the Lord with our wish list, but rather it is dictated in the scripture and intended for the service and pleasure of God Himself. According to the various positions of people in the modes of material nature and according to their spiritual advancement various opportunities are given so that all persons can eventually be elevated.
In the 17th chapter of the Bhagavad-gita it is explained in detail how different persons worship differently due to the modes of nature they are affected by. But the results of their worship are not the same. Those who worship demigods go to the planets of the demigods, those who worship ancestors go with them and those who worship Krishna, God, go to the spiritual world.
In Islam and Christianity the goal is heaven, but heaven is not necessarily the highest goal. Going to Goloka Vrindavan, having a personal and loving relationship with the Lord is higher than having material opulence, beautiful women serving you, and enjoying heavenly sense gratification. Those are not the goals of one practicing Krishna consciousness. The goal is to become an unalloyed lover of God and serve Him for His pleasure.
Worship of "graven images" would include worship of any unauthorized form of the Lord—or something which is really not the Lord—as the Lord. We do neither of these things. Krishna has many forms, which He Himself speaks about in the Srimad-Bhagavatam, which is considered the highest and most complete of all scripture.