What makes a basement finished is the same as what makes a home finished. If the basement has lighting and heat, it may need further electrical work and ducts to meet current code in Seattle.
To help you answer your own question, logically, would you buy a new construction home that only had the studs, heat and some lighting? You might, but you would pay only for what was there and would have to get a construction type loan to finish it?
Based on what you are describing, it is most likely the basement you are considering would not count as finished square footage.
The appraisal is being ordered now. Will be interesting to see if the appraiser notes the lack of carpet or other type of floor coverings as a distinction.
It also depends on the style of home. The one above is a split entry where at least a portion of "the basement" was intended to be a finished space at time of construction It has a fireplace in the room with concrete floors. Obviously intended to be a family room or Rec Room. In Seattle you have many homes where the basement was never intended to be living space at time of construction and the conversion to living space is often difficult to justify, even if there is dryway, heat and windows, due to ceiling height and other factors.
Valuing the basement at the same price per square foot as the main and upper floors, is almost never the case, unless it is a "reverse floor plan" as intention at time of original construction.
A partially finished basement means part of the basement has sheetrock which is mudded taped and painted, floor covering, molding, doors and windows, heat and light.
A finished basement is where all of the above is throughout the basement. You can have an unfinished utility room and still call it a finished basement, but that is about it.