Students may be confused with the Subscripting Multiple Characters explanation. The “Indexing Starts at 0” page presents a visual that helps explain indexing, but students do not see a visual for subscripting until the “FIguring out subscripts” page which comes after the “Subscripting Multiple Characters” page.
The example shows message[2:5] and refers to positions of the subscript, but students won’t understand how a subscript differs from an index without a visual. It would be helpful to move the “Figuring out subscripts” image to this page, or something similar, and update the explanation both in terms of indices and subscripts.
Also, a string without a space would be a better example. If students run the code they may not understand the space is not printed.