Perhaps, "round" steam surface condensers should be more appropriately called "cylindrical" since the main body of the condenser is cylindrical. I have attached an image of a typical "round" or "cylindrical" condenser. Cylindrical condensers are usually shipped fully assembled, and therefore, limited in size due to plate-rolling capabilities and/or shipping restrictions.
Larger steam surface condensers are typically box shaped. These condensers are usually shipped in sections and are field assembled.
I hope this information provides some clarity to you.
Best of luck!