Daniel 2 and 7, parallels
The book is written in prose, but not in the same language throughout. The introduction, chs. 1-2:4, first clause, is written in Hebrew, but from the second clause of the fourth verse of the second chapter to the end of ch. 7 it is in Aramaic, called Syriac in that verse. From the beginning of ch. 8 to the end, in which part the visions are related in the first person, the language is Hebrew.
"Daniel, Book of," Philip Schaff, ed., A Dictionary of the Bible, Philadelphia: American Sunday-School Union, 1880, p. 218.
But now, O LORD, thou art our father; we are the clay, and thou our potter; and we all are the work of thy hand. Isaiah 64:8
Clay clearly symbolizes God's people or in New Testament terms, the Church!
"(Beforetime in Israel, when a man went to enquire of God, thus he spake, Come, and let us go to the seer: for he that is now called a Prophet was beforetime called a Seer.)" 1 Samuel 9:9
"And he [Aaron] shall be thy spokesman unto the people: and he shall be, even he shall be to thee instead of a mouth, and thou shalt be to him instead of God." Exodus 4:16
"And the LORD said unto Moses, See, I have made thee a god to Pharaoh: and Aaron thy brother shall be thy prophet." Exodus 7:1
According to the texts quoted it can be seen that the "eyes of a man and a mouth speaking" of Daniel 7's little horn point to a prophet, a seer and spokesmen, which is what the church is to be for God to the world.
Simply, the symbols used in both Daniel 2 and 7, that point to the fact that the church fell.
By far the most apparent indicator of the fall of the church is Daniel 2's clay's transition from potter's clay to miry or muddy/useless clay. The equivalent transition in Daniel 7, its mouth's transition from a mouth speaking for God to a mouth speaking against God, is not explicitly mentioned. In both cases this transition is tied to the mingling of church and state, the mingling of metal (iron) and non-metal (clay) in Daniel 2 and beast (the 4th non-descript beast) and human (the eyes of a man and a mouth speaking) in Daniel 7. The fact that the iron is not changed in this interaction makes it clear that the iron is not the thing directly making the change in the clay. The change is due to something else not made apparent.