Yes, it's exactly what it sounds like. Photos of members of Congress with Muppets that they resemble (in some cases more than others).
Barney Frank is represented with Fozzie the Bear:
Debbie Wasserman Schultz (using probably the most viciously unflattering photo of her in existence, ouch) is compared to Janice:
Here's my favorite, Eric Cantor with the Newsman: