In the holiest I saw an ark; on the top and sides of it was purest gold. On each end of the ark was a lovely cherub, with its wings spread out over it. Their faces were turned toward each other, and they looked downward. Between the angels was a golden censer. Above the ark, where the angels stood, was an exceeding bright glory, that appeared like a throne where God dwelt. Jesus stood by the ark, and as the saints’ prayers came up to Him, the incense in the censer would smoke, and He would offer up their prayers with the smoke of the incense to His Father. In the ark was the golden pot of manna, Aaron's rod that budded, and the tables of stone which folded together like a book. Jesus opened them, and I saw the ten commandments written on them with the finger of God. On one table were four, and on the other six. The four on the first table shone brighter than the other six. But the fourth, the Sabbath commandment, shone above them all; for the Sabbath was set apart to be kept in honor o…
"And over it the cherubims of glory shadowing the mercyseat; of which we cannot now speak particularly."
Both passages describe the cherubim and the mercy seat, although EGW provides a more detailed description. The connection is valid because both are describing the same object.
"And another angel came and stood at the altar, having a golden censer; and there was given unto him much incense, that he should offer it with the prayers of all saints upon the golden altar which was before the throne. And the smoke of the incense, which came with the prayers of the saints, ascended up before God out of the angel’s hand."
Both passages describe an angel with a golden censer offering incense with the prayers of the saints. The connection is valid because both are describing the same scene.