questions
A toy twisted in the fire. == A toy was twisted in the fire.

Question 1: Do they mean the same thing? If not, what's the difference between them?

Question 2: my analysis: Active voice vs passive voice. In the first case, 'twisted' is in the active form . The toy was rotating by itself. In the second case, 'twisted' is in the passive form. Someone is rotating the toy. We don't know who that someone is, or the writer doesn't want to convey that information. Except for that, their meanings are more or less the same. RIGHT? :P

Question

questions
A toy twisted in the fire. == A toy was twisted in the fire.

Question 1: Do they mean the same thing? If not, what's the difference between them?

Question 2: my analysis: Active voice vs passive voice. In the first case, 'twisted' is in the active form . The toy was rotating by itself. In the second case, 'twisted' is in the passive form. Someone is rotating the toy. We don't know who that someone is, or the writer doesn't want to convey that information. Except for that, their meanings are more or less the same. RIGHT? :P

Answer

A toy twisted in the fire. == A toy was twisted in the fire.
Question 1: Do they mean the same thing? Yes.
2) Almost. You are correct that one is active and the other passive, but in both cases it is very clear that it is the fire that is causing the toy to twist.