It's almost a cruel trick on the part of the artist who makes a
piece like that because the conscientious art patron will be
left feeling "nothing".
Yet, here is the funny part: The people with the big money who
go to museums go there for EXPERIENCES, because they want to
'feel' something. Feeling nothing is "feeling something" and
that's why they appreciate it and give money to the artist to
make more nothings for them to feel. Art culture is a strange
world :) I don't know if Heidegger originated the notion of
"nothing=something" but "Modern art" is definitely of that line
of thinking, all the way through to Jacques Derrida and beyond.
Although, technically speaking, modern art is an era in the
1950s. We've gone beyond Post Modern art... I don't remember
what they call today's art, although the looking-at-a-blank wall
I *think* is in the Post-Modern/Deconstructionalist tradition.