Will I tone my leg muscles if I workout on a stationery bike on high resistance?
No. Nor will you "tone" your leg muscles by jumping on the trampoline with a weighted vest, doing squats with a horse on your back, or sprinting up the side of the Empire State Building. Muscle is muscle - you build it, lose it, or maintain. What you think of as "tone" is visible definition, which has everything to do with body fat.
High intensity intervals are likely to increase your thigh muscle mass, all else being equal. However, that won't make it any more defined. Definition depends on how much body fat is layered under the skin, blunting the outline of the muscle itself.
That's subcutaneous fat. You can't target it, no matter how much Dr. Oz bullshits and says you can. To reduce subcutaneous fat, you have to reduce your overall body fat percentage.
By all means, high-intensity intervals are great. If it's the mirror you're concerned about, though, your calorie balance is what makes the difference.