Definitely. A mixed metaphor is two combined metaphors that are incompatible. Here are a few more examples:
The test is easy; It's not rocket surgery.
Metaphor 1 - It's not rocket science.
Metaphor 2 - It's not brain surgery.
You're sailing close to thin ice.
Metaphor 1 - You're sailing too close to the wind.
Metaphor 2 - You're on thin ice.
Any questions, please let me know! Thank you!
Teacher Charles