In Rome there are two types of folded chasuble in which I've seen. There is this one where it has clearly been cut by the tailor as it was being created and then the other where it is actually folded up in the front and buttoned on the inside.
This is custom...
From Fortescue and O'Connell:
"On certain days the deacon and subdeacon do not wear the dalmatic and tunicle. Instead of these, in greater churches, they wear folded chasubles. The chasubles are now generally folded up in front about half-way and so fixed."