Info 1962 Penny Brown

Excellent observation and question! That is a result of die wear. Over time, the metal in the die moves outward, called die flow. This will actually stretch the details, make them wider even. The bust is actually larger than a new die. Since the metal moves out, the dies must be ground down around the outside. The letters then become at the dies edge which has a bit of taper at this edge making the letters/appear to wrap around it. This shows a VLDS , very late die state, near its useful life. Notice the L of LIBERTY is that way too, it sometimes disappears completely!
Read about the making of the dies and die errors by below here. Might help you figure some of these things out

to the CCF!