It's hard to judge size when there's no frame of reference
Even flying over water can be challenging because it's hard to determine how high you are visually. There's nothing around for you to compare to judge distance. Likewise, in space, it's be very difficult to judge the size of an object unless you saw it close to something else.
Consider the two size estimates you mentioned, 6 meters and 60 meters. Six meters is less than 20 feet - way too small for a manned winged spacecraft. Likewise, 60 meters is closer to 200 feet, which is bigger than a Space Shuttle orbiter and way too big to carry and launch from beneath an aircraft like the article described.