It could be the way you position your images. The first image could be above the second. Or the first could be on the left while the second is on the right. Or the first image could be huge while the second will be much smaller. All those strategies will work. However, most of the time, I think it’s best to use the way the 2 images are interacting. Image 1 will be doing something to image 2. Here are a few examples with some words chosen at random:
Daughter – chair: The daughter is sitting on the chair. / The daughter is smashing the chair on the floor while throwing a tantrum. / The daughter is walking around when she starts to feel tired and decides to sit on the chair. / The daughter is throwing the chair at the next location.
Chair – daughter: The chair is falling from the sky on the daughter’s head. / You first notice a chair, then you notice that the daughter is hiding behind or underneath it. / The character from the previous location walks up to the next and install a chair for the daughter to sit on. / Out of nowhere, perhaps because of poltergeist type phenomenon, a chair flies violently at sudenly toward the poor daughter. / The singer “Cher” (close enough) is angry with her daughter.
Sermon – jealousy: A preacher (reverend Lovejoy from the Simpsons maybe) is delivering a sermon about the sin of jealousy. / A preacher is surprising his girlfriend with another preacher. (A mental note may be needed here to remember that the first word you’re remembering is “sermon” and not “preacher”.) / A preacher is jealous that his sermons aren’t quite as popular as those of another preacher.
Jealousy – sermon: A jealous husband is sermonising his wife. / A jealous husband has to listen to a sermon about how jealousy is a sin. / You’re feeling jealous of everyone who’s luckier than you are and you’re sermonising them about random things just to make yourself feel better. / Some jelly beans (“jelly beans” doesn’t sound exactly like jealousy, but it could be close enough) are being thrown at a preacher delivering a sermon.
Alternative method: In some cases you will probably end up memorizing word 1 + word 2 by visualizing an image that will look more or less exactly the same as it would have been if you were memorizing word 2 + word 1. So for example, you’re memorizing “umbrella” and then “president” by simply imagining Obama using an umbrella. Here it would be quite easy to think that the word “president” comes first instead of second. In those cases, if you don’t want to change your images, it’s possible to remember the correct order of the words with just a quick mental note. “Don’t forget that umbrella comes first!” It might be a somewhat risky strategy, but it will work most of the time. Or maybe the solution can be just about the way you’re conceptualizing those 2 things? You’re first thinking about one, and then you think about its effect on the other. “It’s a good thing that this umbrella is there to protect Obama from the rain.” Or maybe you’re just noticing the umbrella, and then you’re noticing that Obama is underneath?
Important notes: Most of the advice given here will remain valid no matter what kind of memory palace or method you’re choosing to use. The same basic principles will also work if you’re memorizing a deck of cards, the periodic tables, a series of historical dates or whatever.