I think I found the 2. Look at the 7 again and slightly to the right of it. The background dots are colored slightly darker brown compared to the rest of the background. Trying to focus on these brown dots instead of the green 7, you can make out the slightly shifted 2.
Didn’t see it until many people here referred to a 2.
The wall of pure fiction 's cracking in my head,
And the addiction of my world still spreads ~