It starts off showing Iranian children, and then a quick montage of about 20 photos of children suffering in war. The Iranian children then piece together an oversized jigsaw puzzle with those photos of injured children to make a large Palestinian flag under the landmark Azadi Tower in Tehran.
The montage starts at 0:21:
Most of the photos of suffering or injured children I could identify are of Syrian children - suffering under the Iranian-backed Assad regime. (At least one was from the aftermath of an ISIS attack, there may be some from Yemen as well.)
I couldn't verify a single photo as being of Palestinian children.
Somehow, I don't think they really care about Palestinian children.