Duel between lamps
Unfortunately, your assumption is not correct.
Indeed the construction type of the lamp is responsible for the difference, but the size of the glass bulb only plays an indirect role. Some of the brighter lamps only have got a bigger light bulb because their spiral wound filament is bigger (the wire inside of the light bulb which glows while current is flowing).
Depending on the construction type of the light bulb, it shines with a certain brightness at different current strengths. In this case, the oblong light bulb has got a spiral wound filament (the wire inside of the light bulb which glows while current is flowing) with a smaller diameter and thus is shining brighter.
Think about what this means in case of the current strength. In what way is it influenced while transiting the lamps?