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.
so with your 21, do you actually see a colour difference between the numbers and the circle or is it a brightness difference?
That is absolutely fascinating as I can't see any hints of a 2 or how what I see as 7 becomes a 2.
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.