Steampunk Taxidermy - time-travelling rodents. Answered
Chuffy and his Time Machine, Chuffy (mouse) sits in the little carriage on top of the Time Machine (guinea pig). He is having some mechanical problems getting it started, so the hatch on the side of the Guinea pig is open to reveal vintage clockwork cogs that make the Time Machine work, when it hasn't broken down anyway!
Apparently, the donor animals are all natural deaths, including gifts from the maker's cat.