They look similar to me. Do pet trimmers have extra safeguards on them? Or is it about the coarseness of the hair?
What’s a cat trimmer? Is it for shaving your cat? 
One’s for a man, one’s for a lady. 
Usually about $10.
Are they interchangeable?
This pet trimmer looks to have about the same blade design, and teeth per inch, as my battery operated beard trimmer. This one closely resembles my plug-in hair trimmer.
I don’t see any extra safety features on either of them.
Both are overpriced.
This month’s Consumer Report showed the same appliance used two different ways at two different prices - Link (see second item)
According to my daughter, who has experience with both, the only difference is in the blade head, and even that isn’t a real difference, as the blade settings for people and furry animals can overlap.
Odds are, you’ll find one blade head will be fine for you, and another will be fine for kitty.
The only pet clippers I would ever recommend are the Oster A5s with a number 10 blade. Other cheaper models will not last and are unlikely to be up to the kind of jobs people expect of clippers; removing matted hair, etc.
Oster clippers
That was on Headlines with Jay Leno a couple of weeks ago, too. They are both in mail order catalogs that I have received.