You tend to finish the right to left line to the end of the page before moving down any. So if 2 panels are in the same “line” like 2 and 3 are, then you finish out that line before moving down. In a case where one panel is larger and spans multiple lines it’ll generally be laid out to belong to it’s lowest line if it’s on the left side of the page, or the highest line on the right side of the page. So since 12 covers both the line with 9, and the one with 10 and 11 on it you’ll generally read it as belonging to that lower line and it’ll be 12.
You tend to finish the right to left line to the end of the page before moving down any. So if 2 panels are in the same “line” like 2 and 3 are, then you finish out that line before moving down. In a case where one panel is larger and spans multiple lines it’ll generally be laid out to belong to it’s lowest line if it’s on the left side of the page, or the highest line on the right side of the page. So since 12 covers both the line with 9, and the one with 10 and 11 on it you’ll generally read it as belonging to that lower line and it’ll be 12.
Yay an answer that makes sense