[Brightcolours]

Something is off in one post or the other... it doesn't match at all unless that's a toy cellphone in the first pic.

No, these lenses indeed are for large format technical cameras.

 

They are "small" mainly because of 2 things:

1. They are designed with a huge flange distance in mind. So, they can cover a big area on the projection side.
   
2. When you look into equivalency, they have comparatively small apertures. An f8 lens on FF can be very small also.
   

A 3rd reason: they use "old" optics technology. A Canon EF 50mm f1.4 is a lot smaller than a new tech. Sigma 50mm f1.4 Art or Zeiss 50mm f1.4 Milvus.