The good news is that the surgery performed on your girl is completely normal for the treatment of aural haematomas.
Haematomas develop in the ear pinna of dogs usually secondary to an ear infection. The ear is itchy and the dog shakes their head vigorously in an attempt to relieve the itch! This shaking causes tiny blood vessels to haemorrhage and the blood collects between the two pieces of flat cartilage that make up the ear pinna. The heavy accumulation of blood irritates the dog further and they continue to shake their head, which only causes more bleeding and a larger haematoma.
The only way to drain the blood, prevent more from accumulating and avoid a ‘cauliflower ear’ (which is the crinkly appearance of many human boxer’s ears!) is to surgically sandwich the two pieces of cartilage back together. This is done with many sutures so there is no space for blood to re-accumulate. It does look horrible afterwards and I can understand you concern but this is certainly the best way to treat these unsightly and very annoying haematomas.