I see a different profile pic in thumbnail than what appears when I try to open the Pic on WhatsApp. Why does that happen?
The reason for this issue is caused by the synchornization feature and the Internet connection. You can fix it in two ways:
If you have an Android phone, go to Settings > Applications manager > All > WhatsApp > Clear Cache or Clear Data (you will need to re-register)
If you have an iOS or any other phone compatible with WhatsApp, perform a fresh installation of the product.