I don't know about pictures on the web, I haven't look. You can find a nice picture of ground pitchers of both in Clark, Charles, 2001, A guide to the pitcher plants of Sabah. Kota Kibabalu, Natural History Publications (Borneo), 40 p.
I have grown carnivorous plants for many years. There is quite a broad opinion as to whether they should be kept in enclosures with live animals who can potentially become trapped. In nature, frogs are often found living in or around carnivorous plants, using them as insect buffets. Most carnivorous plants are passive and can be used in vivariums with larger frogs with little or no threat. These are heliamphora, butterworts and sundews. Venus flytraps rarely pose a threat to larger frogs, however, pose a very real threat to small thumbnails. They will only live for two or three years successfully, as they require a seasonal dormancy.
Nepenthes should be researched, in my opinion. Ampullarias, in particular, have a peristome which has evolved to prevent animals from climbing out of them (like the rim of a toilet bowl). Frogs are more likely to drown, than become victims of the digestive fluids in the pitchers. Many nepenthes have thin or narrow peristomes which most frogs should be able to navigate. It should be acknowledged, that remains of many different types of animals (not just insects) are found in the pitchers of wild plants, so do your home work.
I would suggest setting up a vivarium for carnivorous plants. They are as interesting, in their own way, grow great in a vivarium, and will not pose a threat to your expensive frogs.