Speculative things that could reverse conclusions/cause and effect around these factors (if they are the case):
1.
More posts on Monday/Tuesday indicate more people are using the site at those times, readers and authors.
There are more posts Monday/Tuesday because there are less posts on Sunday. (Readers become authors in the absence of content.)
2.
People like reading on blogs, or reading blog material which didn’t get cross posted, and that’s where the boost comes from.
Speculative things that could reverse conclusions/cause and effect around these factors (if they are the case):
1.
More posts on Monday/Tuesday indicate more people are using the site at those times, readers and authors.
There are more posts Monday/Tuesday because there are less posts on Sunday. (Readers become authors in the absence of content.)
2.
People like reading on blogs, or reading blog material which didn’t get cross posted, and that’s where the boost comes from.