Room and indoors look basically the same to me.
If room's meant for when a fair amount of the interior is featured, then a simplifying room -> indoors alias wouldn't hurt much, as many of the indoors posts currently meet that criterion.
On the other hand, I'm not sure indoors by itself would do justice to posts that show the room in its entirety, like post #417162 and post #555735. So perhaps an implication instead?
Possible objection to either action: one could argue that post #575077 and post #547387 are too open to be "indoors".
If room ⊆ indoors, and indoors can still apply when you're looking in through a window (post #152846 etc.), then kitchen, bathroom, bedroom and classroom could all imply indoors too.
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