Hi,
The original image is (the link you gave was already a thumbnail) :
igenerac.com/media/com_hikashop/upload/t...rator_guys_white.jpg
The point that I don't understand why you have that issue.
Like I wrote ; there is nothing related to HIkaMarket (even if you are in the vendor page) but it is related to the HikaShop Image Helper.
In that file you will find a line
$estimation = (($origin->width * $origin->height) + ($e_x * $e_y)) * 8;
And if you replace the line just below
$app->enqueueMessage(JText::sprintf('WARNING_IMAGE_TOO_BIG_FOR_MEMORY', $filename));
By
$app->enqueueMessage(JText::sprintf('WARNING_IMAGE_TOO_BIG_FOR_MEMORY', $filename) . ' [' . $estimation . ' / ' . $rest . ']');
It should display the memory estimation and the free memory.
Using that information you should have more elements to understand why this message is displayed.
Regards,