Fix Flux2 reference image mem estimation. (#10905)

Author: comfyanonymous

comfy/model_base.py

@@ -926,7 +926,7 @@ def extra_conds_shapes(self, **kwargs):
         out = {}
         ref_latents = kwargs.get("reference_latents", None)
         if ref_latents is not None:
-            out['ref_latents'] = list([1, 16, sum(map(lambda a: math.prod(a.size()), ref_latents)) // 16])
+            out['ref_latents'] = list([1, 16, sum(map(lambda a: math.prod(a.size()[2:]), ref_latents))])
         return out
 
 class Flux2(Flux):