Something is hidden below. Tell me... what am I saying?
The message here is:
To find this...
...add a checkmark in every box:
Read off the letters each touches, to get C-H-E from the first box, C-K-M from the second, then A-R-K, 'S-Y-O and U-R-S. Altogether, this spells CHECKMARK'S YOURS (note the apostrophe seen before the 'S' in the fourth box).
(The prompt to think in this direction is to note the colour used in the image (green) and 'follow the reward' as per the title - the reward for a correct answer on PSE naturally being a green checkmark!)
Thank you very much!