[Samsung Galaxy Nexus] scary alien:
Don't have an N4 (wish I did ;)), but I diff'd efrant's misc.img files above:

C:\Temp\downloads>diff od-[COLOR="Red"]locked[/COLOR]-misc.txt od-[COLOR="Blue"]unlocked[/COLOR]-misc.txt
26c26
< 0040000 4e41 5244 494f 2d44 4f42 544f 0021 0000 [COLOR="red"]0000 [/COLOR]0000 0000 0000 0000 0000 0000 0000
---
> 0040000 4e41 5244 494f 2d44 4f42 544f 0021 0000 [COLOR="Blue"]0001 [/COLOR]0000 0000 0000 0000 0000 0000 0000
29,32c29,32
< 0043000 0000 0000 0000 0000 0000 0000 [COLOR="red"]f000 [/COLOR]0001 a000 0000 183c 88f2 [COLOR="red"]001f [/COLOR]0000 0000 0000
< 0043040 000a 0000 0000 0000 000a 0000 [COLOR="red"]001f [/COLOR]0000 0000 0000 f7d0 88f4 0000 0000 0009 0000
< 0043100 0000 0000 12e8 88f2 0000 0000 [COLOR="red"]001b [/COLOR]0000 [COLOR="red"]0001 [/COLOR]0000 [COLOR="red"]001f [/COLOR]0000 0000 0000 1284 88f2
< 0043140 f788 88f4 0529 88f1 [COLOR="red"]0001 [/COLOR]0000 0000 0000 0000 0000 f839 88f4 0001 0000 05f4 88f1
---
> 0043000 0000 0000 0000 0000 0000 0000 [COLOR="blue"]c000 [/COLOR]0001 a000 0000 183c 88f2 [COLOR="blue"]001c [/COLOR]0000 0000 0000
> 0043040 000a 0000 0000 0000 000a 0000 [COLOR="blue"]001c [/COLOR]0000 0000 0000 f7d0 88f4 0000 0000 0009 0000
> 0043100 0000 0000 12e8 88f2 0000 0000 [COLOR="blue"]001a [/COLOR]0000 [COLOR="blue"]0008 [/COLOR]0000 [COLOR="blue"]001c [/COLOR]0000 0000 0000 1284 88f2
> 0043140 f788 88f4 0529 88f1 [COLOR="blue"]0008 [/COLOR]0000 0000 0000 0000 0000 f839 88f4 0001 0000 05f4 88f1
35c35
< 0043300 0000 0000 [COLOR="Red"]3548 88f4 f817 3133 3932[/COLOR] 0030 [COLOR="red"]0004 [/COLOR]0000 f82c 88f4 57c8 88f2 0000 0000
---
> 0043300 0000 0000 [COLOR="Blue"]0000 0000 3200 3838 3630[/COLOR] 0030 [COLOR="blue"]0000 [/COLOR]0000 f82c 88f4 57c8 88f2 0000 0000
37,44c37,44
< 0043400 2484 88f4 00d1 88f1 0013 0000 011d 88f1 018c 88f4 f95c 88f4 335b 3231 3039 205d
< 0043440 0000 88f4 0001 0100 6166 7473 6f62 746f 203a 656f 206d 6f6c 6b63 000a bdb3 88f0
< 0043500 0000 0000 0000 0000 f880 88f4 7460 88f3 ffff ffff 0001 0000 24c8 88f4 24d4 88f4
< 0043540 2484 88f4 1468 88f4 0000 0000 be17 88f0 0000 0000 0000 0000 4f58 88f4 bfdf 88f0
< 0043600 0001 0000 0000 0000 3838 88f4 623f 88f0 2354 88f2 2480 88f4 2354 88f2 7460 88f3
< 0043640 ffff ffff 0001 0000 24c8 88f4 247c 88f4 24a8 88f4 5f74 88f4 e349 88f0 be17 88f0
< 0043700 0000 0000 0000 0000 4f58 88f4 bfdf 88f0 2354 88f2 2480 88f4 2354 88f2 e603 88f0
< 0043740 2354 88f2 65df 88f0 4b4f 5941 0000 9200 0000 0000 7460 88f3 0040 0000 147c 88f4
---
> 0043400 2484 88f4 00d1 88f1 0015 0000 011d 88f1 0000 0000 f95c 88f4 325b 3838 3630 5d30
> 0043440 0020 0000 0000 0000 6166 7473 6f62 746f 203a 656f 206d 6e75 6f6c 6b63 000a 6d6f
> 0043500 000d 88f1 3548 88f4 f897 88f4 0002 0000 0004 0000 fd91 88f0 0000 0000 7460 88f3
> 0043540 a0ac 88f4 0002 0000 0004 0000 b979 88f0 0000 0000 0000 0000 0000 0000 0002 0000
> 0043600 58e4 88f3 f8a1 88f0 0000 0000 7460 88f3 ffff ffff 0001 0000 a0bc 88f4 24d4 88f4
> 0043640 2484 88f4 1468 88f4 000a 0000 8198 0004 7460 88f3 001c 88f4 0001 0000 00a0 88f4
> 0043700 24d4 88f4 2484 88f4 e9ce 88cd 0000 0000 0000 0000 84bc 88f3 0000 88b0 b4f0 88f0
> 0043740 0133 2000 0023 0000 0000 0000 2767 0000 e9ce 88cd be17 88f0 f3c7 88f0 f35c 88f0

Hopefully, the larger blocks of differences are actually related to the lock/unlock image vs. anything else.

Cheers and best of luck!

edit: I tried color-coding some of the differences (there were just too many in the last sections, so I skipped those ;) :))