In Mary Shelley's Frankenstein, what is the monster’s reaction when he sees himself reflected in a pool of water?

In chapter 4, volume II of
Frankenstein the creature was still in awe of the cottagers, and he
fully expressed his admiration towards them during his moments of reflection. He liked
their looks, their actions, and even the utterances that later he  identified as
words.

The creature was in a state of bliss. He was
connecting emotionally with the family and he created a fantasy in his head in which he
was one of the De Laceys. Shortly after he had begun to experience those feelings of
love and affection, he had the horrid experience of seeing his reflection in a pool of
water.

In the monster's
words:

...
but how was I terrified, when I viewed myself in a transparent pool! At first I started
back, unable to believe that it was indeed I who was reflected in the mirror; and when I
became fully convinced that I was in reality the monster that I am, I was filled with
the bitterest sensations of despondence and mortification. Alas! I did not yet entirely
know the fatal effects of this miserable
deformity.

The creature's
words demonstrate that he suffered two huge disappointments: First, having to break from
the fantasy world that he had created, in which he was a part of the De Lacey family.
Second, having to accept that he was a far cry from what he would have wanted to
be.

It must have been a devastating blow for the creature
to know that he possessed the needs, wants, and desires of a human and yet he had to
live hiding from humanity itself. The reflection in the water was more than just the
monster facing himself, but it also represented the creature's sad acceptance of his
reality and his destiny.