When you create Clustered Index data is physically sorted 
based on the column used in clustered index.

don't know what is logical sort data.

As it is explained in the Answer #1, The Clustered Index
uses the Physical Sorting, just like the Page Index at the
Beginning of your book, but The Logical sorting means it
will be done with the Non Clustered Indices, as you all know
the data in the server stored on the multi page files,
because the amount of data stored on the database is huge,
So in case of the logical sorting depending upon say query
results the records are at your disposal which you have got
after filtering using a where clause, then the data is
coming from different pages and there is no continuation
like SNO column in case case of select *, So the pages where
the desired data is found are actually will hold the
references, means the record say #3, from page #3, will hold
the address of the Previous record address as well as the
next record address just like your Double Linked List Nodes,
I hope now logical sorting is explained by me here.