I will beg my ignorance as to what is done in a psychiatric ICU. If you have skills with rapid physical assessment, management of multiple IV lines, titration of hemodynamically active continuous drips, advanced cardio-pulmonary resus skills and management of invasive airways then I would could see an ED manager seeing that as comparable to ICU skills.
I believe the skills you have from what I believe happens in a psych ICU would be very valuable in the ED, but probably not considered what most consider "ICU".
So your second question is would I consider hiring you into the ED? Possibly, pysch skills are great, but if you didn't have great skills in the areas I mentioned above, I would probably need to treat you largely as unexperienced until you learned the non-pysch skills.
When I went from adult telemetry to NICU, I was treated mostly as a new graduate that didn't know anything. I appreciated this. Turns out my time management and knowledge of cardiac monitors was useful but not much else.
Let me emphasize again, that if your psych ICU utilized the skills I listed in the first paragraph, I would consider those "ICU" skills and you would be at the top of the list.