Watching from my room, I saw that my little brother was a ball of energy after his nap Which two things are being compared
The two things being compared are "my little brother" and "a ball of energy."
In the given sentence, the two things being compared are "my little brother" and "a ball of energy." The speaker is referring to their brother's high level of activity or liveliness by comparing him to a ball of energy.
In the given sentence, two things are being compared:
1. "my little brother"
2. "a ball of energy"