At 23:19, Forty draws "8:52" on Joe's arm, the 2 drawn in a crude cursive style. At 35:00 and 36:36, it is shown on his arm as he walks by, written in a slightly different style. Again, it is shown at 40:25, this time written in cursive again, but with a more pronounced loop in the 2 than in previous shots. At 44:26, it is shown again with the same loop. At 45:42, it has yet another variation.
Joe sees that Delilah's phone has facial recognition, however, her phone is either an iPhone 7 Plus or 8 Plus and those do not have the capability for facial recognition.