That box on the mast just above the number plate on Signal 224-2 was part of the mechanism for a lower arm. In 1954, EQ crossover in Endicott was not interlocked, but was the site of eastward and westward telephone train order signals.
Sometime earlier (someone with an earlier, like 1930, timetable, please check this out) EQ was doubtless a tower controlling an interlocking around milepost 221 or 222. If that was the case, then an approach signal to EQ would probably have had two arms, and that signal was probably 224-2.
One other point, though, is that an intermediate signal governing the approach to an interlocking would have its two arms closer together, and the lamp on the lower arm would have been on the track side of the mast. It appears that the lower lamp bracket is on the field side of this mast.
This signal looks more like one of the characteristic Erie interlocking home signals with a space where the middle arm would have been located. If that was the case, then it might at one time been a home signal at an interlocked crossover with no provision for a medium-speed aspect.
Someone please check an old timetable and see if there was a manned or remote interlocking at MP 224. If so, that would explain that additional mechanism on the mast. Otherwise, the mast and base could have been moved there from somewhere else.