Could my two front teeth veneers be made smaller? (photos)

Veneers can broaden your smile, your smile would have been better with 10 porcelain veneers, it would have looked better.
If you shorten your front 2 porcelain veneers, your front teeth might look wider, if you insist just do like a 1/4 millimeter at the time, once you cut the veneer shorter, there is no way to get back to original length, unless you redo your front veneers over! 
If you shorten the front 2 teeth, think about shortening 4 front teeth!! It will look better.

Hi:Your smile looks nice.  Your dentist can easily shorten your two front teeth, however the two front teeth should be a little bit longer than the side teeth.  I would not make them any shorter.  In terms of 8 vs. 10 teeth, if you smile any bigger than your posted picture, then 10 would be best, if this is as big as you smile then 8 seems to be good enough.Best, Dr. Maddahi