The original meaning is not Page, but mind, head, or brain. I think that it is more like mind.
Let's recall the shell bone script for character Head (Post 41)
only a head, no body. It is more like a physical head, no any mind activities.
The big seal script for character Page
on the top is the head, and middle is face (or eye some experts believe), the bottom is the body.
The small seal script for character Page is
which is a face on the top part, and two legs on the bottom half.
I have to point out that in the shell bone script time (3000+ years ago), it was Neolithic age and Bronze Age, in the north China, rock painting was popular.
both rock paintings are from Yanshan, Inner Mongolia, China.
How could the meaning of the character have changed from mind to page? I have not found a good explanation.
What I guess is that the ancient Chinese thought that the rock painting is more like a mind activity, so they created a big head with big eye to emphasize the mind activity. But there are tens thousands rock paintings, they took one painting to be one unit. After people invented paper making technology, they might have copied the rock paintings on paper. One painting on one page, so people use this character to represent Page.
The clerical script (after Paper making technology invented) for character Page,
Traditional song typeface for Page
very similar to clerical script.
Its simplified song typeface is
Its pinyin is Ye4.
頁 or 页 means Page, has no any meaning of mind/head/brain at all, which is not common. Most characters keep the old meaning in some degree but 頁/页 is not.
So most Chinese don't know it meant Mind originally.