I have one. I don't use it anymore since moving to Hawai'i, but it was great. Easy to use, small, and it looks good. I don't know much about humidity, but it kept my 'ukulele in good shape for the year I was in Cali. Just use the provided syringe to inject water into it and use the velcro buttons to stick it in your case. As for pictures - it doesn't get any more exciting that what you see there. Just velcro on the back (it comes with self-adhesive buttons so you can put those in your case and still unvelcro the humidifier to fill it).
Totally go for it.