Parallel or not?

I have a general query – when given a figure like this it seems obvious that the topmost line is not parallel to the bottom line. Infact it is sloping downward when going from right to left.

In the GRE, can we go ahead with this observation even if it is not explicitly stated that the lines are not parallel?

Can we deduce from this figure that x < y?

You’d ideally want to center your “assumptions” around geometric reasoning rather than by sight — especially on the gre.

No, That would not be allowed to assume in GRE and GRE math guide specifically state that too.