why 'e' instead of 'este'?
'e' is the short/informal version of 'este'
I Feel as if the "e" is being omitted. Can someone supply an article explaining the rules.
Is this idiomatic?
No, it's just a normal sentence the course creators came up with.
"e" the same as "este"
"e" a kind of abbreviation of "este"
the meaning in the sentence does not change at all