What do the tag-specific hex codes in the c files represent?

[joellyons]

What do the tag-specific hex codes in the c files represent? For example, in tag25h9.c, tag 0's code is represented as 0x156f1f4. I assumed that each bit in that number (1010101101111000111110100) represented a block in tag 0's visual representation starting at top left and moving left to right, top to bottom, where 1 is a black square and 0 is white.

But, if I render it that way, I end up with this:

instead of what I see in apriltag-imgs, which is this:

Are the graphics in apriltag-imgs outdated? Or am I misinterpreting the numeric values in tag25h9.c?