</font><font color="blue" class="small">( I don't know how you can determine the speed based on that picture. At least half the belt system is covered by guards ... )</font>
I am using the other half for a guess. So, what do you think about the size of small pulley which is not seen there? Unless its dia. of small pulley is more than 5 times smaller than that of big pulley, its speed of this mower in attachment can not be as high as that of finish mowers people are used to. So, with your estimated speed just looking at the picture, this mower in attachment is "finishing short"? or "finishing rough"? Answer to this will determine what it is; Rough Mower (bush hog) of Fine Mower (finish mower.)