I believe the image was indicating an opinion from the poster that to upgrade to iOS 8 would or at least could be, in their view, precipitous to a circumstance that would be not entirely favourable, and, having been offered the benefits in the email sent to the recipient, the absence of counterpoints to the nature and tone of said email may constitute a feeling that one has been lead into a course of action that when looked at in retrospect, with all things considered, in the event of a more negative outcome, one might describe the experience in terms that may form at the very least an unexpected result in the context of the sum of all previously factors surrounding the device, its software and the process of raising the iOS version number upwards.
But the character pictured famously said all that in fewer words, and about something else. i.e. ("It's a trap!")