Well, that depends. Is he looking at these pictures for sexual
arousal, out of admiration?, curiosity?, because he's a
transvestite?, or for other reasons?
It really depends on why he is looking at them. If it is for
sexual arousal, he could simply find transvestism arousing. There
is nothing inherently wrong with being a transvestite or being
sexually aroused by transvestism. Oftentimes, people also have the
misconception that by being a transvestite or by being sexually
aroused by transvestism means that the individual is gay. However,
transvestites and people who are aroused by transvestism can be any
gender and any sexual orientation.
Of course, your husband may simply be looking out of curiosity -
transvestism isn't very visible in most societies. He could find
transvestites interesting or admire their courage to be who they
are. He could also possibly be a transvestite himself who either
finds the pictures arousing or is looking for tips on future
transvestite clothing items for himself or both.