Yes, it is possible to verify which skipasses have been loaded onto your Snowitcard. To do so, log into your account and visit the My Snowitcards section. Here, you will find a list of all the cards associated with your account, along with each cardholder's name and date of birth.
By clicking on Skipass List, you can view the skipasses linked to each card. In the details of each skipass, you will also find the confirmation number of the specific skipass. This confirmation number may be required at the ticket office in case of need.
This way, you can check whether the skipass has been correctly loaded and keep all the important information handy.