I will be making a bridal shower cake for my future neice. I would like to attach copies of the engagement photo on the cake. Would it be okay to laminate the photo and attach to the buttercream. If I use the edible printer from walmart. Do I just press the image into the buttercream. What do you think about fondant plaques. Please give me your suggestions.

Any of the ways you suggested would work. I have had issues with printing the photo on edible paper and placing it directly on the buttercream. I've heard a lot of people use the edible paper on a fondant/gumpaste plaque.