If you care more than others, you have a big heart, and should give to our charity..
Wishful Thinking
The example you provided is an example of a fallacy known as the "appeal to emotion" fallacy, specifically the "flattery" variation. This fallacy attempts to persuade someone by appealing to their emotions or ego rather than presenting a valid argument or evidence. In this case, the speaker is implying that the listener has a big heart and cares more than most, which may make the listener feel inclined to donate to the charity. However, this flattery does not provide any logical or factual reasons to support the claim, and instead relies on manipulating the listener's emotions.