picture (one) as (something)

1. To imagine that one is or might be a certain type of person or thing. I always pictured you as a lawyer when you got older. I lived next to them my whole life—I can't picture them as killers!

2. To create an image in one's mind of one being or looking a certain way. I can't help but laugh picturing my brother the hippie as some straight-laced police officer. Growing up, whenever my mom talked about my cousin being in the Navy Seals, I always pictured him as a literal seal wearing a military uniform.

picture someone as someone or something

to imagine someone as someone or a type of person; to form a mental picture of someone as someone or a type of person. Just picture me as Santa Claus! I can't picture you as a doctor.