this is not homura, not the hair ,not the breast .

-Same hair style
-Same clothes
-Soul Gem

She IS Homura

Not just that, the artist tagged her as akemi_homura, so that pretty much settles it right there.

as416108932 said:
this is not homura, not the hair ,not the breast .

I think you are crazy. :D

it's the size of breasts, he meant Homura cannot be this big

In a few years it's possible.

Homura's breast is quite normal, the author and audience didn't mentions her breast size too much as some other characters. For example, if someone draw a Bamami, he will clearly draw a big breast because that's obvious. But Homura is different, maybe the "BreastSize_AkemiHomura" propertiy in the artist's head is not Initialized, so he would directly assign it a default value, usually this is fine because most artist's "BreastSize_Undefined" value is quite near Homu's acutual breast, expect there is a unusual brian, in this picture.