How to calculate power consumed by an electrical device in a specified amount of time?
If a car is travelling at 40 mph it doesn't mean it travels at 40 mph per minute.

If a TV is consuming 140 watts it means it consumes 140 joules per second.

What you get charged for by your utility company is joules and that is oddly (but acceptably) converted (without mathematical error) to watt seconds or more conveniently watt hours or kilowatt hours.

Maybe that is what confused you?