here-docs ALWAYS start in the line after the first (statement delimiting) semicolon.

> I guess I'm wrong to assume those periods are concatenation operators, but if so, what's going on here?

You're not wrong it's a concat. e evals the replacement part before inclusion!

Check the regex docs for details.

> Does it mean the same as this? ...

I think so. I didn't try, but why didn't you?