I'm not M-C, but can offer a little help on this:
"JE T'(heart) VACHEMENT AVEC TOUS TES DEFAUTS!"
This is like when we write "I (heart)..." In this case "I love cow stuff" (cows is "vache"). The second half is "with all your..." not sure what "defauts" is. Sorry, it's been 20 years since college French (YIKES! Am I THAT old???).
and
"Ce superbe mug est réalisé en céramique émaillée soigneusement décorée d'un décor "vache".
"This superb mug is realized in punctuated carefully decorated ceramic of a setting "cow".
So they are saying that they have a really nice mug with a cow on it and you will probably like it since you like cows.
Cecelia