Let's say that a company plans a picnic in a "semi-park" area. I.e. - it is a tree-lined public thoroughfare that many people including Jews, walk through. (I added this fact b/c I have seen some discussions regarding "mar'it ayin" that there is leniency if the location is in a non-Jewish area. Someone, feel free to edit and provide link to Mi Yodeya questions on this, if there are any. Have trouble locating these links, now.)
The company serves non-kosher food at the picnic. The employee is required to attend the picnic as the company takes "attendance" and considers it a "work day".
Is there a problem of "mar'it ayin" if a Jewish employee attends the picnic, but doesn't eat any of the food?