This looks to me like polyuria which is an increase in the liquid portion of the dropping, the fecal portion is still formed so therefore it is not diarrhea. Has the bird eaten any fruits or veggies with a high water content or is the bird showing any other signs of illness? If it continues I would take the bird to an avian vet for assessment.
Well recently I bought them some new foods (Nutriberries which contain cranberries, apricots, dates, and seeds and pellets | Kaytee Garden Veggie Treat) they don't eat fresh fruits or veggies no matter what I do except my 2 other birds didn't have the same reaction as her... She also drank water twice in a row so maybe that could be it too..?The photo will not open for me, but as mentioned in the post above; if the dropping is formed, but has a large urine portion, it is not diarrhea. If the polyuria persists regardless of diet, especially if accompanied by other symptoms as well, the cause needs to be determined by an avian vet. Let us know if the droppings return to normal.