Certain statements are loshon hara when said regarding one person, yet are perfectly acceptable when said regarding someone else. For example, to say that a business man studies Torah five hours a day is obviously not derogatory. However, to say this of a kollel member who is assumed to be spending the entire day engrossed in Torah study would be derogatory. Similarly, it would be forbidden to relate the amount of tzedakah given by an individual, if that amount is considered respectable only for a man of lesser means.
[There may be factors which would prohibit relating such information even when it is clearly complimentary. For example, people who give charity generously often do not want that fact to become public knowledge. See Day 34.]
Sefer Chofetz Chaim, 4 Tishrei, page 56