Same as in post #1298364. Now that I notice, the clothes are the same too. Are these based on some official art of Madoka and Sayaka as kids, and if so, from what specifically?
It's from the light novel it explains some details about Madoka and Sayaka's childhood, how they met, how Sayaka protected her even from then, and how Madoka suffers some self-esteem issues because she compares herself to her.
