Is that a Restripia? If so, it is potted
way too deep... and, in too large of a pot.... Looks like it may be a little too damp as well, and although they do seem to like moisture, they don't want sopping-wet moisture. Did you repot this when you got it, or did it come this way? What is the name on the tag? That will help us guide you to the proper culture of this guy.
Mine gets a good bit of morning sun (eastern), but you will wanna *gradually* introduce (any orchid) to brighter light.
I will say, that there are some "shorter stemmed" Restripias, that should look almost like this when potted, but I don't think there are many... As far as I know, most have slightly long stems... Which is why I'd like to know which species (or hybrid?) it is, so I can get you the proper advice. (I will pm an expert right now
)
And, no, usually (as far as I know) orchids don't drop their leaves
before the growing season begins... When it's over, there are some (not yours, tho
) that do, in fact, lose their leaves... But not these guys!