I have the following phrase:

Auf den ersten Blick bietet der Herbst alles andere als Wohlbehagen.

The question is why the usage of accusative and not dative in the part "auf den ersten Blick".

I explain. First, that particular part is a designation. It gives context but is not part of the kernel of the phrase which is "der herbst bietet alles andere als Wohlbehagen". Second, the use of the prepositon "auf" which can be used with both dative but also with accusative, though AFAIK the later happens only when there is a action of motion involved in the meaning. But here there is no motion. So why not "auf dem ersten Blick"?

Thanks