Because MAS says it is a requirement.
3. The reproduction of any currency note
(a) shall, unless the reproduction is in an electronic form
(i) be at least 150% of both the length and width of the
genuine
currency note when the reproduction is enlarged; or
(ii) be not more than 60% of both the length and width of the
genuine
currency note when the reproduction is reduced in size;
(b) shall, when the reproduction is enlarged, reduced in size or to
be viewed
at an angle, be depicted proportionally;
(c) may be depicted at various angles, except that, where the
whole
currency note is depicted flat to camera, the reproduction shall
contain
the word SPECIMEN in black and bold lettering diagonally
across
the reproduction and which shall not cover any part of the
portrait; and
(d) shall not be by way of duplex printing (that is, nothing shall
appear on
the reverse of the reproduction that may give the impression that
it is
a genuine currency note).
