你非暖阳却照我心房
[nĭ fēi nuăn yáng què zhào wŏ xīn fáng]
It implies 'Although you're not the sunshine itself, you still enlighten my heart', which suggests that even though someone isn't exactly what this person needed, their existence brings light and warmth to this person's life, perhaps symbolizing friendship that is as important as sunlight.