Yes, He is the express image of God Almighty. Let us look at this passage which speaks of the Lord Jesus::
"Who, being in the form of God, thought it not robbery to be equal with God: But made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: And being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross" (Phil.2:6-8).
The Greek word translated "form" means "the form by which by which a person or thing strikes the vision; the external appearance" (Thayer's Greek English Lexicon).
So when His servants will see the One sitting in "the throne of God and of the Lamb" they will see the form of the Lord Jesus and at the same time they will be seeing the form of God:
"And there shall be no more curse: but the throne of God and of the Lamb shall be in it; and his servants shall serve him: And they shall see his face; and his name shall be in their foreheads" (Rev.22:3-4).
When His servants look at the Lamb they will see the external appearance of God. And it is impossible that anyone could see the Lamb that way unless He is in fact God.
Therefore, you are right when you say that the Lord Jesus is the express image of God Almighty.
Put that backwards, and it's saying (according to error) that G-d is in the outward physical form of a man, if the outward physical form of Yeshua is what is meant here. Obviously, it's not. So error here is in ASSUMING that a physical form is meant, but what is actually meant by the outward form of G-d in this case, is the SPIRIT SEED, because G-d was IN CHRIST (Spirit Seed) reconciling all men unto Himself.
Indeed this is why, He said, when you've seen ME (the Spirit Seed) you've seen the Father, because the Father IS Spirit, and according to the law of the seed, every seed must bear fruit after it's own kind. His own kind is the Father, which is Spirit, therefore the Son of G-d is SPIRIT. And this is why we were told that this revelation which can only come from the Father is the foundation of His many-membered body/temple being built. And in this sense He, the Spirit Seed, is equal to, or the same as the Father, in NATURE, not identity.