Please change the appearance of the language indicator at the top of the block so that it looks different to a code comment. This could be by centre- or right-aligning it, or by using a distinctive style, e.g. border or underline.
As it stands, it doesn't look like a header, and it's easy to select it along with the code (the normal way, via PRIMARY selection - the button only copies to CLIPBOARD selection, which is too cumbersome for normal use).