Right at the top of the window is the beautiful image of God as Alpha - the Beginning and Omega - the End.
The whole window shows the creation story from the beginning to the end from a Christian understanding. The beginning is shown in panel 11a with the first day of creation. The end is shown in panel 2j Christ in Majesty.
I Am Alpha and Omega
The term Alpha and Omega comes from the phrase "I am Alpha and Omega" (Koiné Greek: "ἐγώ εἰμι τὸ Ἄλφα καὶ τὸ Ὦ"), an appellation of Jesus[2] in the Book of Revelation (verses 1:8, 21:6, and 22:13). The first part of this phrase ("I am the Alpha and Omega") is first found in Chapter 1 verse 8 ("1:8"), and is found in every manuscript of Revelation that has 1:8. Several later manuscripts repeat "I am the Alpha and Omega" in 1:11 too, but do not receive support here from most of the oldest manuscripts, including the Alexandrine, Sinaitic, and Codex Ephraemi Rescriptus.