You are under an impression.
This makes you say, “I am under a
particular
impression”, and this sentence seems to say, to yourself at
least, under what impression you are.
As though you were referring to a picture
ready || in
readiness in your mind
and said,
155.
“This is
it” || and said, “This is what my
impression is like”. ¤
Whereas you have only pointed to your impression.
In our case
), saying “I notice the
particular colour of this wall” is like drawing, say, a black
rectangle enclosing a small patch of the wall and thereby designating
that patch as a sample for further use.